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Laguna Beach, CA.
At some point in history, all of this was submerged in our ocean. This explains the many fossils encrusted in the stone, found along the trails.
Where I am standing, they call this point the Top of the World. It was an approximate 2 mile stretch that felt like 8 miles with its enormous hills.
All of the hills are worth it considering the exhilarating trek downhill at approximately 20 miles per hour. Also there's this view of the Pacific ocean. Beyond the water, you can see the island of Catalina. To the right are the Palo Verde estates, Signal Hill and then downtown Long Beach harbor.
I do favor this place for an intense workout for those that wish to deplete their glycogen stores. Try going earlier in the morning or maybe even at night. Mid-morning, the place is filled with a horde of hikers and other cyclists. Not exactly my cup of tea.
1: X marks the spot 2: waiting our turn 3: PACU slumber 4: "booboo meemee" (Avanese translation: my booboo! my ginormous bandaid! )
UPDATE: Ava has been diagnosed with GSD or "glycogen storage disease". it is a rare liver disease genetically passed on. there are several 'types' of GSD. We await further biopsy results giving us this info so we will know what her treatment plan will be. For now her million $$$ miracle drug is "Argo cornstarch" from the grocery store.
UN FUNGO INSIGNIFICANTE MA NON INUTILE
Troppo spesso si parla di funghi solo dal punto di vista gastronomico, ma essi hanno una valenza naturalistica importante nell'equilibrio naturale di un bosco.
I funghi sono composti dall’80/90% di acqua e da diverse sostanze minerali, vitamine a-b-d, zuccheri, potassio, ferro, rame, composti organici del carbonio, glicogeno, chitina, ecc. Come tutti gli esseri viventi anche essi, per crescere e riprodursi, hanno bisogno di nutrirsi e nel fare questo, svolgono un’azione importantissima per l’ecosistema che li ospita.
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AN INSIGNIFICANT BUT NOT USELESS MUSHROOM
Too often we talk about mushrooms only from a gastronomic point of view, but they have an important naturalistic value in the natural balance of a forest.
Mushrooms are composed of 80/90% water and various mineral substances, vitamins a-b-d, sugars, potassium, iron, copper, organic carbon compounds, glycogen, chitin, etc. Like all living beings, they too, to grow and reproduce, need to feed and in doing this, they perform a very important action for the ecosystem that hosts them.
CANON EOS 600D con ob. CANON EF 100 mm f./2,8 L Macro IS USM
Things are picking up at the Seasonal Pond at Creamer's Field. I guess spring has sprung!
The wood frogs are thawed (remember they freeze solid in the winter) and are now getting frisky. They were making quite a song.
These guys have one of the more extraordinary adaptations to survive the winter. In the fall as the temperatures fall, their bodies convert their sugars into a glycogen a kind of antifreeze. The cell walls are then lined with this antifreeze to keep the cells from bursting when they freeze. Then they borrow into the mud and freeze solid for the winter only to thaw out and resume life in the spring.
Yes, that is bacon on a maple bar; it is what they would call the maple-bacon bar. You may also notice Kellogg's Fruit Loops and Post Cereal's Cinnamon Toast Crunch, strategically settled on their own spherical-delights.
This is what a PWO inevitably leads to; replenishing the glycogen stores, spiking that insulin for salutary results. I suppose you can say that I Doughnut care too much about counting calories when a selection like this is provided.
It still surprises me to how much one can get away with by adopting ultra-low-carb sources of sustenance for the majority of the week. Add a few days of resistance training or HIIT and you can get away with even more.
Tomorrow's agenda, triathlon; cycling; swimming; and tennis... then likely, even more donuts.
Springtime in Interior Alaska! The wood frogs are awake and mating.
Wood frogs have one of the more impressive survival strategies. In the fall they convert the sugars in their body into glycogen to coat their cell walls so they will not rupture when they freeze. They then borrow into mud or leave litter and freeze into a frogcycle.
They live for 5 years so they perform this magic 5 times.
This is a male croaking to attract a mate.
The wood frogs of interior Alaska have to be one of the most amazing adaptations to our extreme climate.
In the fall as the water cools, they convert the sugars in their blood to a glycogen a natural antifreeze. It is pushed into the cells of the frog. When you get frost bite, it isn't just fact things get frozen, it is the individual cells rupture when the fluids expand as it freezes. So with the cells with their antifreeze the inside of the cells are protected.
Then as the cold of winter approaches the frogs bury themselves into the mud and then they freeze solid, no sign of life, not even a heart beat.
Then when the spring comes and the water warms the frogs come back to life. They go thru this freeze thaw cycle up to 5 times.
These frogs have just come back to life and are looking for a mate. So for a few weeks the seasonal pond is alive with croaking frogs.
To me it is a real sign of life finding a way to survive aginst all odds.
My last two postings have been galls caused by kinds of fungus. When I was out photowalking a couple days ago I saw many galls like this on the goldenrod plants so I took a shot and then googled it when I got home.
The gall turns out to be caused by the Goldenrod Gall Fly, Eurosta solidagnis. In the spring female flies deposit eggs singly in rapidly growing goldenrod stems. The eggs hatch after several days and the tiny white to cream-colored larvae begin feeding inside the stem in which they hatched. The larval fly’s saliva contains a chemical which is thought to mimic plant hormones so it causes the plant to grow abnormally. In response to the insect’s feeding, the plant increases cell production at the site of injury, forming a gall that becomes apparent about 3 weeks after the eggs are laid.
Initially the gall is the same size and color as the stem, but eventually grows to nearly the size of a golf ball. As each gall expands, the solitary larva inside eats out the center of the gall to form a chamber in which it lives. The galls don’t seem to have a debilitating effect on the goldenrods plants, which still bloom despite the gall. In the fall the gall turns brown and hard. The larvae feed throughout the summer, molting twice and growing to about ¼ inch long. In the fall, in preparation for its exit the following spring, the mature larva chews a tunnel to the gall’s surface, leaving just a thin layer over the opening to the outside.
The larva enters diapause as a third instar larva to overwinter inside the gall. Cold temperatures induce the larva to convert glycogen into glycerol and sorbitol, which serves as antifreeze by reducing the water content in the body so ice crystals do not form and cause cell injury. In the early spring the larvae pupate inside the gall, with the adult flies emerging in mid-spring. During the approximately 10 to 14 days they live, their only activity is to mate and lay eggs on young goldenrod stems.
Source and more info: wimastergardener.org/article/goldenrod-gall-fly-eurosta-s...
The Cheetah (Acinonyx jubatus) is an a typical member of the cat family (Felidae) that hunts by speed rather than by stealth or pack tactics. It is the fastest of all terrestrial animals and can reach speeds of up to 110 km/h in short bursts. Its body has evolved for speed, with long legs, an elongated spine, adapted claws to grip the ground and a long tail for balance.
It takes a lot of distinct biology to be able to accelerate from 0 to 70 mph in under three seconds: Cheetahs have extra large livers to better mobilize the glycogen molecules that provide quick bursts of energy. They have enlarged adrenal glands, lungs, nasal passages, and hearts to accommodate extra oxygen in order to fuel their muscles. A comparatively long, heavy tail provides a counter balance for tight turns at top speeds. Without claw sheaths, their claws stick out even when retracted - providing cleat-like grip to the bottom of their feet. And fused tibia and fibula bones in the cheetah’s legs make them more stable when sprinting after prey.
This beautiful lone Cheetah was photographed on an early morning game drive in the Maasai Mara Game reserve, Kenya.
An update on my daughter who was in the hospital for a few days. She was allowed to go home three evenings ago, though the medical staff still aren't completely sure of the cause of the problem. She has a follow-up appointment in September, so hopefully she and we will know more at that time. Meanwhile, I feel totally drained, ha!
A couple of days ago, on 25 August, 10 of us arrived at a friend's house, ready to go north of Calgary to near Sundre, for a few hours of botanizing, This was the second visit to Judy Osborne's for a few of us, me included. The previous trip was on 30 June 2015. By now, of course, a lot of the wildflowers are finished, but I found enough other things to photograph, including a distant, beautiful Red-tailed Hawk, a Wood Frog and a Yellowjacket (wasp), plus a few of the plants in my friends' garden at the beginning and end of the day. No scenery shots, as the visibility was so bad due to the smoke. There was nothing I could do about the single blade of grass that goes right across the Wood Frog's face. If I had tried to move it with my hiking pole, you know what the frog would have done : )
"Similar to other northern frogs that enter dormancy close to the surface in soil and/or leaf litter, wood frogs can tolerate the freezing of their blood and other tissues. Urea is accumulated in tissues in preparation for overwintering, and liver glycogen is converted in large quantities to glucose in response to internal ice formation. Both urea and glucose act as cryoprotectants to limit the amount of ice that forms and to reduce osmotic shrinkage of cells. Frogs can survive many freeze/thaw events during winter if no more than about 65% of the total body water freezes." From Wikipedia.
en.wikipedia.org/wiki/Wood_frog
Thanks so much, Judy, for having us out on your beautiful property again. It was a most enjoyable day, despite the dreadful, smoke-filled air (from forest fires burning in Washington State, northwest US). We look forward to being out there again next year! Many thanks, too, to Barry, who drove a few of us out there and back to Calgary. A long, long drive and it was much appreciated!
From my walk today at Creamer's wildlife refuge.
This is a wood frog just waking up from being a frogsicle as winter approaches, they first convert all the sugars into glycogen, a natural antifreeze, borrow into the mud and freeze for the winter.
She was pretty sluggish and near a wad of grass that had a long tail weasel stalking. Unfortunately, the weasel was faster than me to get a shot. In the end the weasel was concerned about my presence and gave up and disappeared.
A camel (from Latin: camelus and Greek: κάμηλος (kamēlos) from Ancient Semitic: gāmāl) is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provide food (milk and meat) and textiles (fiber and felt from hair). Camels are working animals especially suited to their desert habitat and are a vital means of transport for passengers and cargo. There are three surviving species of camel. The one-humped dromedary makes up 94% of the world's camel population, and the two-humped Bactrian camel makes up 6%. The wild Bactrian camel is a separate species and is now critically endangered.
The word camel is also used informally in a wider sense, where the more correct term is "camelid", to include all seven species of the family Camelidae: the true camels (the above three species), along with the "New World" camelids: the llama, the alpaca, the guanaco, and the vicuña, which belong to the separate tribe Lamini. Camelids originated in North America during the Eocene, with the ancestor of modern camels, Paracamelus, migrating across the Bering land bridge into Asia during the late Miocene, around 6 million years ago.
Taxonomy
Extant species
Three species are extant:
ImageCommon nameScientific nameDistribution
Bactrian camelCamelus bactrianusDomesticated; Central Asia, including the historical region of Bactria.
Dromedary / Arabian camelCamelus dromedariusDomesticated; the Middle East, Sahara Desert, and South Asia; introduced to Australia
Wild Bactrian camelCamelus ferusRemote areas of northwest China and Mongolia
Biology
The average life expectancy of a camel is 40 to 50 years. A full-grown adult dromedary camel stands 1.85 m (6 ft 1 in) at the shoulder and 2.15 m (7 ft 1 in) at the hump. Bactrian camels can be a foot taller. Camels can run at up to 65 km/h (40 mph) in short bursts and sustain speeds of up to 40 km/h (25 mph). Bactrian camels weigh 300 to 1,000 kg (660 to 2,200 lb) and dromedaries 300 to 600 kg (660 to 1,320 lb). The widening toes on a camel's hoof provide supplemental grip for varying soil sediments.
The male dromedary camel has an organ called a dulla in his throat, a large, inflatable sac that he extrudes from his mouth when in rut to assert dominance and attract females. It resembles a long, swollen, pink tongue hanging out of the side of the camel's mouth. Camels mate by having both male and female sitting on the ground, with the male mounting from behind. The male usually ejaculates three or four times within a single mating session. Camelids are the only ungulates to mate in a sitting position.
Ecological and behavioral adaptations
Camel humps store fat, which are used as nourishment when food is scarce. If a camel uses the fat inside the hump, the hump will become limp and droop down
Camels do not directly store water in their humps; they are reservoirs of fatty tissue. When this tissue is metabolized, it yields a greater mass of water than that of the fat processed. This fat metabolization, while releasing energy, causes water to evaporate from the lungs during respiration (as oxygen is required for the metabolic process): overall, there is a net decrease in water.
Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water. The dromedary camel can drink as seldom as once every 10 days even under very hot conditions, and can lose up to 30% of its body mass due to dehydration. Unlike other mammals, camels' red blood cells are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: a 600 kg (1,300 lb) camel can drink 200 L (53 US gal) of water in three minutes.
Camels are able to withstand changes in body temperature and water consumption that would kill most other mammals. Their temperature ranges from 34 °C (93 °F) at dawn and steadily increases to 40 °C (104 °F) by sunset, before they cool off at night again. In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day. Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a rete mirabile, a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain. Camels rarely sweat, even when ambient temperatures reach 49 °C (120 °F). Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight in water, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance.
When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water. Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.
Domesticated camel calves lying in sternal recumbency, a position that aids heat loss
The camel's thick coat insulates it from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating. During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn. The camel's long legs help by keeping its body farther from the ground, which can heat up to 70 °C (158 °F). Dromedaries have a pad of thick tissue over the sternum called the pedestal. When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body.
Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their translucent third eyelid (also known as the nictitating membrane). The camels' gait and widened feet help them move without sinking into the sand.
The kidneys and intestines of a camel are very efficient at reabsorbing water. Camels' kidneys have a 1:4 cortex to medulla ratio. Thus, the medullary part of a camel's kidney occupies twice as much area as a cow's kidney. Secondly, renal corpuscles have a smaller diameter, which reduces surface area for filtration. These two major anatomical characteristics enable camels to conserve water and limit the volume of urine in extreme desert conditions. Camel urine comes out as a thick syrup, and camel faeces are so dry that they do not require drying when used to fuel fires.
The camel immune system differs from those of other mammals. Normally, the Y-shaped antibody molecules consist of two heavy (or long) chains along the length of the Y, and two light (or short) chains at each tip of the Y. Camels, in addition to these, also have antibodies made of only two heavy chains, a trait that makes them smaller and more durable. These "heavy-chain-only" antibodies, discovered in 1993, are thought to have developed 50 million years ago, after camelids split from ruminants and pigs. Camels suffer from surra caused by Trypanosoma evansi wherever camels are domesticated in the world: 2 and resultantly camels have evolved trypanolytic antibodies as with many mammals. In the future, nanobody/single-domain antibody therapy will surpass natural camel antibodies by reaching locations currently unreachable due to natural antibodies' larger size.: 788 Such therapies may also be suitable for other mammals.: 788 Tran et al. 2009 provides a new reference test for surra (T. evansi) of camel. They use recombinant Invariant Surface Glycoprotein 75 (rISG75, an Invariant Surface Glycoprotein) and ELISA. The Tran test has high test specificity and appears likely to work just as well for T. evansi in other hosts, and for a pan-Trypanozoon test, which would also be useful for T. b. brucei, T. b. gambiense, T. b. rhodesiense, and T. equiperdum.
Genetics
The karyotypes of different camelid species have been studied earlier by many groups, but no agreement on chromosome nomenclature of camelids has been reached. A 2007 study flow sorted camel chromosomes, building on the fact that camels have 37 pairs of chromosomes (2n=74), and found that the karyotype consisted of one metacentric, three submetacentric, and 32 acrocentric autosomes. The Y is a small metacentric chromosome, while the X is a large metacentric chromosome.
The hybrid camel, a hybrid between Bactrian and dromedary camels, has one hump, though it has an indentation 4–12 cm (1.6–4.7 in) deep that divides the front from the back. The hybrid is 2.15 m (7 ft 1 in) at the shoulder and 2.32 m (7 ft 7 in) tall at the hump. It weighs an average of 650 kg (1,430 lb) and can carry around 400 to 450 kg (880 to 990 lb), which is more than either the dromedary or Bactrian can.
According to molecular data, the wild Bactrian camel (C. ferus) separated from the domestic Bactrian camel (C. bactrianus) about 1 million years ago. New World and Old World camelids diverged about 11 million years ago. In spite of this, these species can hybridize and produce viable offspring. The cama is a camel-llama hybrid bred by scientists to see how closely related the parent species are. Scientists collected semen from a camel via an artificial vagina and inseminated a llama after stimulating ovulation with gonadotrophin injections. The cama is halfway in size between a camel and a llama and lacks a hump. It has ears intermediate between those of camels and llamas, longer legs than the llama, and partially cloven hooves. Like the mule, camas are sterile, despite both parents having the same number of chromosomes.
Evolution
The earliest known camel, called Protylopus, lived in North America 40 to 50 million years ago (during the Eocene). It was about the size of a rabbit and lived in the open woodlands of what is now South Dakota. By 35 million years ago, the Poebrotherium was the size of a goat and had many more traits similar to camels and llamas. The hoofed Stenomylus, which walked on the tips of its toes, also existed around this time, and the long-necked Aepycamelus evolved in the Miocene. The split between the tribes Camelini, which contains modern camels and Lamini, modern llamas, alpacas, vicuñas, and guanacos, is estimated to have occurred over 16 million years ago.
The ancestor of modern camels, Paracamelus, migrated into Eurasia from North America via Beringia during the late Miocene, between 7.5 and 6.5 million years ago. During the Pleistocene, around 3 to 1 million years ago, the North American Camelidae spread to South America as part of the Great American Interchange via the newly formed Isthmus of Panama, where they gave rise to guanacos and related animals. Populations of Paracamelus continued to exist in the North American Arctic into the Early Pleistocene. This creature is estimated to have stood around nine feet (2.7 metres) tall. The Bactrian camel diverged from the dromedary about 1 million years ago, according to the fossil record.
The last camel native to North America was Camelops hesternus, which vanished along with horses, short-faced bears, mammoths and mastodons, ground sloths, sabertooth cats, and many other megafauna as part of the Quaternary extinction event, coinciding with the migration of humans from Asia at the end of the Pleistocene, around 13–11,000 years ago.
Domestication
Like horses, camels originated in North America and eventually spread across Beringia to Asia. They survived in the Old World, and eventually humans domesticated them and spread them globally. Along with many other megafauna in North America, the original wild camels were wiped out during the spread of the first indigenous peoples of the Americas from Asia into North America, 10 to 12,000 years ago; although fossils have never been associated with definitive evidence of hunting.
Most camels surviving today are domesticated. Although feral populations exist in Australia, India and Kazakhstan, wild camels survive only in the wild Bactrian camel population of the Gobi Desert.
History
When humans first domesticated camels is disputed. Dromedaries may have first been domesticated by humans in Somalia or South Arabia sometime during the 3rd millennium BC, the Bactrian in central Asia around 2,500 BC, as at Shar-i Sokhta (also known as the Burnt City), Iran. A study from 2016, which genotyped and used world-wide sequencing of modern and ancient mitochondrial DNA (mtDNA), suggested that they were initially domesticated in the southeast Arabian Peninsula, with the Bactrian type later being domesticated around Central Asia.
Martin Heide's 2010 work on the domestication of the camel tentatively concludes that humans had domesticated the Bactrian camel by at least the middle of the third millennium somewhere east of the Zagros Mountains, with the practice then moving into Mesopotamia. Heide suggests that mentions of camels "in the patriarchal narratives may refer, at least in some places, to the Bactrian camel", while noting that the camel is not mentioned in relationship to Canaan. Heide and Joris Peters reasserted that conclusion in their 2021 study on the subject.
In 2009-2013, excavations in the Timna Valley by Lidar Sapir-Hen and Erez Ben-Yosef discovered what may be the earliest domestic camel bones yet found in Israel or even outside the Arabian Peninsula, dating to around 930 BC. This garnered considerable media coverage, as it is strong evidence that the stories of Abraham, Jacob, Esau, and Joseph were written after this time.
The existence of camels in Mesopotamia—but not in the eastern Mediterranean lands—is not a new idea. The historian Richard Bulliet did not think that the occasional mention of camels in the Bible meant that the domestic camels were common in the Holy Land at that time. The archaeologist William F. Albright, writing even earlier, saw camels in the Bible as an anachronism.
The official report by Sapir-Hen and Ben-Joseph notes:
The introduction of the dromedary camel (Camelus dromedarius) as a pack animal to the southern Levant ... substantially facilitated trade across the vast deserts of Arabia, promoting both economic and social change (e.g., Kohler 1984; Borowski 1998: 112–116; Jasmin 2005). This ... has generated extensive discussion regarding the date of the earliest domestic camel in the southern Levant (and beyond) (e.g., Albright 1949: 207; Epstein 1971: 558–584; Bulliet 1975; Zarins 1989; Köhler-Rollefson 1993; Uerpmann and Uerpmann 2002; Jasmin 2005; 2006; Heide 2010; Rosen and Saidel 2010; Grigson 2012). Most scholars today agree that the dromedary was exploited as a pack animal sometime in the early Iron Age (not before the 12th century [BC])
and concludes:
Current data from copper smelting sites of the Aravah Valley enable us to pinpoint the introduction of domestic camels to the southern Levant more precisely based on stratigraphic contexts associated with an extensive suite of radiocarbon dates. The data indicate that this event occurred not earlier than the last third of the 10th century [BC] and most probably during this time. The coincidence of this event with a major reorganization of the copper industry of the region—attributed to the results of the campaign of Pharaoh Shoshenq I—raises the possibility that the two were connected, and that camels were introduced as part of the efforts to improve efficiency by facilitating trade.
Textiles
Main article: Camel hair
Desert tribes and Mongolian nomads use camel hair for tents, yurts, clothing, bedding and accessories. Camels have outer guard hairs and soft inner down, and the fibers are sorted by color and age of the animal. The guard hairs can be felted for use as waterproof coats for the herdsmen, while the softer hair is used for premium goods. The fiber can be spun for use in weaving or made into yarns for hand knitting or crochet. Pure camel hair is recorded as being used for western garments from the 17th century onwards, and from the 19th century a mixture of wool and camel hair was used.
Military uses
Main article: Camel cavalry
By at least 1200 BC the first camel saddles had appeared, and Bactrian camels could be ridden. The first saddle was positioned to the back of the camel, and control of the Bactrian camel was exercised by means of a stick. However, between 500 and 100 BC, Bactrian camels came into military use. New saddles, which were inflexible and bent, were put over the humps and divided the rider's weight over the animal. In the seventh century BC the military Arabian saddle evolved, which again improved the saddle design slightly.
Military forces have used camel cavalries in wars throughout Africa, the Middle East, and into the modern-day Border Security Force (BSF) of India (though as of July 2012, the BSF planned the replacement of camels with ATVs). The first documented use of camel cavalries occurred in the Battle of Qarqar in 853 BC. Armies have also used camels as freight animals instead of horses and mules.
The East Roman Empire used auxiliary forces known as dromedarii, whom the Romans recruited in desert provinces. The camels were used mostly in combat because of their ability to scare off horses at close range (horses are afraid of the camels' scent), a quality famously employed by the Achaemenid Persians when fighting Lydia in the Battle of Thymbra (547 BC).
19th and 20th centuries
A photo of Bulgarian military-transport camels in 1912
A camel caravan of the Bulgarian military during the First Balkan War, 1912
The United States Army established the U.S. Camel Corps, stationed in California, in the 19th century.[19] One may still see stables at the Benicia Arsenal in Benicia, California, where they nowadays serve as the Benicia Historical Museum. Though the experimental use of camels was seen as a success (John B. Floyd, Secretary of War in 1858, recommended that funds be allocated towards obtaining a thousand more camels), the outbreak of the American Civil War in 1861 saw the end of the Camel Corps: Texas became part of the Confederacy, and most of the camels were left to wander away into the desert.
France created a méhariste camel corps in 1912 as part of the Armée d'Afrique in the Sahara in order to exercise greater control over the camel-riding Tuareg and Arab insurgents, as previous efforts to defeat them on foot had failed. The Free French Camel Corps fought during World War II, and camel-mounted units remained in service until the end of French rule over Algeria in 1962.
In 1916, the British created the Imperial Camel Corps. It was originally used to fight the Senussi, but was later used in the Sinai and Palestine Campaign in World War I. The Imperial Camel Corps comprised infantrymen mounted on camels for movement across desert, though they dismounted at battle sites and fought on foot. After July 1918, the Corps began to become run down, receiving no new reinforcements, and was formally disbanded in 1919.
In World War I, the British Army also created the Egyptian Camel Transport Corps, which consisted of a group of Egyptian camel drivers and their camels. The Corps supported British war operations in Sinai, Palestine, and Syria by transporting supplies to the troops.
The Somaliland Camel Corps was created by colonial authorities in British Somaliland in 1912; it was disbanded in 1944.
Bactrian camels were used by Romanian forces during World War II in the Caucasian region. At the same period the Soviet units operating around Astrakhan in 1942 adopted local camels as draft animals due to shortage of trucks and horses, and kept them even after moving out of the area. Despite severe losses, some of these camels ended up as far west as to Berlin itself.
The Bikaner Camel Corps of British India fought alongside the British Indian Army in World Wars I and II.
The Tropas Nómadas (Nomad Troops) were an auxiliary regiment of Sahrawi tribesmen serving in the colonial army in Spanish Sahara (today Western Sahara). Operational from the 1930s until the end of the Spanish presence in the territory in 1975, the Tropas Nómadas were equipped with small arms and led by Spanish officers. The unit guarded outposts and sometimes conducted patrols on camelback.
21st century competition
At the King Abdulaziz Camel Festival, in Saudi Arabia, thousands of camels are paraded and are judged on their lips and humps. The festival also features camel racing and camel milk tasting and has combined prize money of $57m (£40m). In 2018, 12 camels were disqualified from the beauty contest after it was discovered their owners had tried to improve their camel's good looks with injections of botox, into the animals' lips, noses and jaws. In 2021 over 40 camels were disqualified for acts of tampering and deception in beautifying camels.
Food uses
Dairy
Main article: Camel milk
Camel milk is a staple food of desert nomad tribes and is sometimes considered a meal itself; a nomad can live on only camel milk for almost a month.
Camel milk can readily be made into yogurt, but can only be made into butter if it is soured first, churned, and a clarifying agent is then added. Until recently, camel milk could not be made into camel cheese because rennet was unable to coagulate the milk proteins to allow the collection of curds. Developing less wasteful uses of the milk, the FAO commissioned Professor J.P. Ramet of the École Nationale Supérieure d'Agronomie et des Industries Alimentaires, who was able to produce curdling by the addition of calcium phosphate and vegetable rennet in the 1990s. The cheese produced from this process has low levels of cholesterol and is easy to digest, even for the lactose intolerant.
Camels provide food in the form of meat and milk. Approximately 3.3 million camels and camelids are slaughtered each year for meat worldwide. A camel carcass can provide a substantial amount of meat. The male dromedary carcass can weigh 300–400 kg (661–882 lb), while the carcass of a male Bactrian can weigh up to 650 kg (1,433 lb). The carcass of a female dromedary weighs less than the male, ranging between 250 and 350 kg (550 and 770 lb). The brisket, ribs and loin are among the preferred parts, and the hump is considered a delicacy. The hump contains "white and sickly fat", which can be used to make the khli (preserved meat) of mutton, beef, or camel. On the other hand, camel milk and meat are rich in protein, vitamins, glycogen, and other nutrients making them essential in the diet of many people. From chemical composition to meat quality, the dromedary camel is the preferred breed for meat production. It does well even in arid areas due to its unusual physiological behaviors and characteristics, which include tolerance to extreme temperatures, radiation from the sun, water paucity, rugged landscape and low vegetation. Camel meat is reported to taste like coarse beef, but older camels can prove to be very tough, although camel meat becomes tenderer the more it is cooked.
Camel is one of the animals that can be ritually slaughtered and divided into three portions (one for the home, one for extended family/social networks, and one for those who cannot afford to slaughter an animal themselves) for the qurban of Eid al-Adha.
The Abu Dhabi Officers' Club serves a camel burger mixed with beef or lamb fat in order to improve the texture and taste. In Karachi, Pakistan, some restaurants prepare nihari from camel meat. Specialist camel butchers provide expert cuts, with the hump considered the most popular.
Camel meat has been eaten for centuries. It has been recorded by ancient Greek writers as an available dish at banquets in ancient Persia, usually roasted whole. The Roman emperor Heliogabalus enjoyed camel's heel. Camel meat is mainly eaten in certain regions, including Eritrea, Somalia, Djibouti, Saudi Arabia, Egypt, Syria, Libya, Sudan, Ethiopia, Kazakhstan, and other arid regions where alternative forms of protein may be limited or where camel meat has had a long cultural history. Camel blood is also consumable, as is the case among pastoralists in northern Kenya, where camel blood is drunk with milk and acts as a key source of iron, vitamin D, salts and minerals.
A 2005 report issued jointly by the Saudi Ministry of Health and the United States Centers for Disease Control and Prevention details four cases of human bubonic plague resulting from the ingestion of raw camel liver.
Australia
Camel meat is also occasionally found in Australian cuisine: for example, a camel lasagna is available in Alice Springs. Australia has exported camel meat, primarily to the Middle East but also to Europe and the US, for many years. The meat is very popular among East African Australians, such as Somalis, and other Australians have also been buying it. The feral nature of the animals means they produce a different type of meat to farmed camels in other parts of the world, and it is sought after because it is disease-free, and a unique genetic group. Demand is outstripping supply, and governments are being urged not to cull the camels, but redirect the cost of the cull into developing the market. Australia has seven camel dairies, which produce milk, cheese and skincare products in addition to meat.
Religion
Islam
Main article: Animals in Islam
Muslims consider camel meat halal (Arabic: حلال, 'allowed'). However, according to some Islamic schools of thought, a state of impurity is brought on by the consumption of it. Consequently, these schools hold that Muslims must perform wudhu (ablution) before the next time they pray after eating camel meat. Also, some Islamic schools of thought consider it haram (Arabic: حرام, 'forbidden') for a Muslim to perform Salat in places where camels lie, as it is said to be a dwelling place of the Shaytan (Arabic: شيطان, 'Devil'). According to Abu Yusuf (d.798), the urine of camel may be used for medical treatment if necessary, but according to Abū Ḥanīfah, the drinking of camel urine is discouraged.
The Islamic texts contain several stories featuring camels. In the story of the people of Thamud, the prophet Salih miraculously brings forth a naqat (Arabic: ناقة, 'milch-camel') out of a rock. After the prophet Muhammad migrated from Mecca to Medina, he allowed his she-camel to roam there; the location where the camel stopped to rest determined the location where he would build his house in Medina.
Judaism
See also: Food and drink prohibitions
According to Jewish tradition, camel meat and milk are not kosher. Camels possess only one of the two kosher criteria; although they chew their cud, they do not possess cloven hooves: "But these you shall not eat among those that bring up the cud and those that have a cloven hoof: the camel, because it brings up its cud, but does not have a [completely] cloven hoof; it is unclean for you."
Cultural depictions
What may be the oldest carvings of camels were discovered in 2018 in Saudi Arabia. They were analysed by researchers from several scientific disciplines and, in 2021, were estimated to be 7,000 to 8,000 years old. The dating of rock art is made difficult by the lack of organic material in the carvings that may be tested, so the researchers attempting to date them tested animal bones found associated with the carvings, assessed erosion patterns, and analysed tool marks in order to determine a correct date for the creation of the sculptures. This Neolithic dating would make the carvings significantly older than Stonehenge (5,000 years old) and the Egyptian pyramids at Giza (4,500 years old) and it predates estimates for the domestication of camels.
Distribution and numbers
A view into a canyon: many camels gathering around a watering hole
Camels in the Guelta d'Archei, in northeastern Chad
There are approximately 14 million camels alive as of 2010, with 90% being dromedaries. Dromedaries alive today are domesticated animals (mostly living in the Horn of Africa, the Sahel, Maghreb, Middle East and South Asia). The Horn region alone has the largest concentration of camels in the world, where the dromedaries constitute an important part of local nomadic life. They provide nomadic people in Somalia and Ethiopia with milk, food, and transportation.
Over one million dromedary camels are estimated to be feral in Australia, descended from those introduced as a method of transport in the 19th and early 20th centuries. This population is growing about 8% per year; it was estimated at around 700,000 in 2008. Representatives of the Australian government have culled more than 100,000 of the animals in part because the camels use too much of the limited resources needed by sheep farmers.
A small population of introduced camels, dromedaries and Bactrians, wandered through Southwestern United States after having been imported in the 19th century as part of the U.S. Camel Corps experiment. When the project ended, they were used as draft animals in mines and escaped or were released. Twenty-five U.S. camels were bought and exported to Canada during the Cariboo Gold Rush.
The Bactrian camel is, as of 2010, reduced to an estimated 1.4 million animals, most of which are domesticated. The Wild Bactrian camel is a separate species and is the only truly wild (as opposed to feral) camel in the world. The wild camels are critically endangered and number approximately 1400, inhabiting the Gobi and Taklamakan Deserts in China and Mongolia.
A camel (from Latin: camelus and Greek: κάμηλος (kamēlos) from Ancient Semitic: gāmāl) is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provide food (milk and meat) and textiles (fiber and felt from hair). Camels are working animals especially suited to their desert habitat and are a vital means of transport for passengers and cargo. There are three surviving species of camel. The one-humped dromedary makes up 94% of the world's camel population, and the two-humped Bactrian camel makes up 6%. The wild Bactrian camel is a separate species and is now critically endangered.
The word camel is also used informally in a wider sense, where the more correct term is "camelid", to include all seven species of the family Camelidae: the true camels (the above three species), along with the "New World" camelids: the llama, the alpaca, the guanaco, and the vicuña, which belong to the separate tribe Lamini. Camelids originated in North America during the Eocene, with the ancestor of modern camels, Paracamelus, migrating across the Bering land bridge into Asia during the late Miocene, around 6 million years ago.
Taxonomy
Extant species
Three species are extant:
ImageCommon nameScientific nameDistribution
Bactrian camelCamelus bactrianusDomesticated; Central Asia, including the historical region of Bactria.
Dromedary / Arabian camelCamelus dromedariusDomesticated; the Middle East, Sahara Desert, and South Asia; introduced to Australia
Wild Bactrian camelCamelus ferusRemote areas of northwest China and Mongolia
Biology
The average life expectancy of a camel is 40 to 50 years. A full-grown adult dromedary camel stands 1.85 m (6 ft 1 in) at the shoulder and 2.15 m (7 ft 1 in) at the hump. Bactrian camels can be a foot taller. Camels can run at up to 65 km/h (40 mph) in short bursts and sustain speeds of up to 40 km/h (25 mph). Bactrian camels weigh 300 to 1,000 kg (660 to 2,200 lb) and dromedaries 300 to 600 kg (660 to 1,320 lb). The widening toes on a camel's hoof provide supplemental grip for varying soil sediments.
The male dromedary camel has an organ called a dulla in his throat, a large, inflatable sac that he extrudes from his mouth when in rut to assert dominance and attract females. It resembles a long, swollen, pink tongue hanging out of the side of the camel's mouth. Camels mate by having both male and female sitting on the ground, with the male mounting from behind. The male usually ejaculates three or four times within a single mating session. Camelids are the only ungulates to mate in a sitting position.
Ecological and behavioral adaptations
Camel humps store fat, which are used as nourishment when food is scarce. If a camel uses the fat inside the hump, the hump will become limp and droop down
Camels do not directly store water in their humps; they are reservoirs of fatty tissue. When this tissue is metabolized, it yields a greater mass of water than that of the fat processed. This fat metabolization, while releasing energy, causes water to evaporate from the lungs during respiration (as oxygen is required for the metabolic process): overall, there is a net decrease in water.
Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water. The dromedary camel can drink as seldom as once every 10 days even under very hot conditions, and can lose up to 30% of its body mass due to dehydration. Unlike other mammals, camels' red blood cells are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: a 600 kg (1,300 lb) camel can drink 200 L (53 US gal) of water in three minutes.
Camels are able to withstand changes in body temperature and water consumption that would kill most other mammals. Their temperature ranges from 34 °C (93 °F) at dawn and steadily increases to 40 °C (104 °F) by sunset, before they cool off at night again. In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day. Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a rete mirabile, a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain. Camels rarely sweat, even when ambient temperatures reach 49 °C (120 °F). Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight in water, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance.
When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water. Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.
Domesticated camel calves lying in sternal recumbency, a position that aids heat loss
The camel's thick coat insulates it from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating. During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn. The camel's long legs help by keeping its body farther from the ground, which can heat up to 70 °C (158 °F). Dromedaries have a pad of thick tissue over the sternum called the pedestal. When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body.
Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their translucent third eyelid (also known as the nictitating membrane). The camels' gait and widened feet help them move without sinking into the sand.
The kidneys and intestines of a camel are very efficient at reabsorbing water. Camels' kidneys have a 1:4 cortex to medulla ratio. Thus, the medullary part of a camel's kidney occupies twice as much area as a cow's kidney. Secondly, renal corpuscles have a smaller diameter, which reduces surface area for filtration. These two major anatomical characteristics enable camels to conserve water and limit the volume of urine in extreme desert conditions. Camel urine comes out as a thick syrup, and camel faeces are so dry that they do not require drying when used to fuel fires.
The camel immune system differs from those of other mammals. Normally, the Y-shaped antibody molecules consist of two heavy (or long) chains along the length of the Y, and two light (or short) chains at each tip of the Y. Camels, in addition to these, also have antibodies made of only two heavy chains, a trait that makes them smaller and more durable. These "heavy-chain-only" antibodies, discovered in 1993, are thought to have developed 50 million years ago, after camelids split from ruminants and pigs. Camels suffer from surra caused by Trypanosoma evansi wherever camels are domesticated in the world: 2 and resultantly camels have evolved trypanolytic antibodies as with many mammals. In the future, nanobody/single-domain antibody therapy will surpass natural camel antibodies by reaching locations currently unreachable due to natural antibodies' larger size.: 788 Such therapies may also be suitable for other mammals.: 788 Tran et al. 2009 provides a new reference test for surra (T. evansi) of camel. They use recombinant Invariant Surface Glycoprotein 75 (rISG75, an Invariant Surface Glycoprotein) and ELISA. The Tran test has high test specificity and appears likely to work just as well for T. evansi in other hosts, and for a pan-Trypanozoon test, which would also be useful for T. b. brucei, T. b. gambiense, T. b. rhodesiense, and T. equiperdum.
Genetics
The karyotypes of different camelid species have been studied earlier by many groups, but no agreement on chromosome nomenclature of camelids has been reached. A 2007 study flow sorted camel chromosomes, building on the fact that camels have 37 pairs of chromosomes (2n=74), and found that the karyotype consisted of one metacentric, three submetacentric, and 32 acrocentric autosomes. The Y is a small metacentric chromosome, while the X is a large metacentric chromosome.
The hybrid camel, a hybrid between Bactrian and dromedary camels, has one hump, though it has an indentation 4–12 cm (1.6–4.7 in) deep that divides the front from the back. The hybrid is 2.15 m (7 ft 1 in) at the shoulder and 2.32 m (7 ft 7 in) tall at the hump. It weighs an average of 650 kg (1,430 lb) and can carry around 400 to 450 kg (880 to 990 lb), which is more than either the dromedary or Bactrian can.
According to molecular data, the wild Bactrian camel (C. ferus) separated from the domestic Bactrian camel (C. bactrianus) about 1 million years ago. New World and Old World camelids diverged about 11 million years ago. In spite of this, these species can hybridize and produce viable offspring. The cama is a camel-llama hybrid bred by scientists to see how closely related the parent species are. Scientists collected semen from a camel via an artificial vagina and inseminated a llama after stimulating ovulation with gonadotrophin injections. The cama is halfway in size between a camel and a llama and lacks a hump. It has ears intermediate between those of camels and llamas, longer legs than the llama, and partially cloven hooves. Like the mule, camas are sterile, despite both parents having the same number of chromosomes.
Evolution
The earliest known camel, called Protylopus, lived in North America 40 to 50 million years ago (during the Eocene). It was about the size of a rabbit and lived in the open woodlands of what is now South Dakota. By 35 million years ago, the Poebrotherium was the size of a goat and had many more traits similar to camels and llamas. The hoofed Stenomylus, which walked on the tips of its toes, also existed around this time, and the long-necked Aepycamelus evolved in the Miocene. The split between the tribes Camelini, which contains modern camels and Lamini, modern llamas, alpacas, vicuñas, and guanacos, is estimated to have occurred over 16 million years ago.
The ancestor of modern camels, Paracamelus, migrated into Eurasia from North America via Beringia during the late Miocene, between 7.5 and 6.5 million years ago. During the Pleistocene, around 3 to 1 million years ago, the North American Camelidae spread to South America as part of the Great American Interchange via the newly formed Isthmus of Panama, where they gave rise to guanacos and related animals. Populations of Paracamelus continued to exist in the North American Arctic into the Early Pleistocene. This creature is estimated to have stood around nine feet (2.7 metres) tall. The Bactrian camel diverged from the dromedary about 1 million years ago, according to the fossil record.
The last camel native to North America was Camelops hesternus, which vanished along with horses, short-faced bears, mammoths and mastodons, ground sloths, sabertooth cats, and many other megafauna as part of the Quaternary extinction event, coinciding with the migration of humans from Asia at the end of the Pleistocene, around 13–11,000 years ago.
Domestication
Like horses, camels originated in North America and eventually spread across Beringia to Asia. They survived in the Old World, and eventually humans domesticated them and spread them globally. Along with many other megafauna in North America, the original wild camels were wiped out during the spread of the first indigenous peoples of the Americas from Asia into North America, 10 to 12,000 years ago; although fossils have never been associated with definitive evidence of hunting.
Most camels surviving today are domesticated. Although feral populations exist in Australia, India and Kazakhstan, wild camels survive only in the wild Bactrian camel population of the Gobi Desert.
History
When humans first domesticated camels is disputed. Dromedaries may have first been domesticated by humans in Somalia or South Arabia sometime during the 3rd millennium BC, the Bactrian in central Asia around 2,500 BC, as at Shar-i Sokhta (also known as the Burnt City), Iran. A study from 2016, which genotyped and used world-wide sequencing of modern and ancient mitochondrial DNA (mtDNA), suggested that they were initially domesticated in the southeast Arabian Peninsula, with the Bactrian type later being domesticated around Central Asia.
Martin Heide's 2010 work on the domestication of the camel tentatively concludes that humans had domesticated the Bactrian camel by at least the middle of the third millennium somewhere east of the Zagros Mountains, with the practice then moving into Mesopotamia. Heide suggests that mentions of camels "in the patriarchal narratives may refer, at least in some places, to the Bactrian camel", while noting that the camel is not mentioned in relationship to Canaan. Heide and Joris Peters reasserted that conclusion in their 2021 study on the subject.
In 2009-2013, excavations in the Timna Valley by Lidar Sapir-Hen and Erez Ben-Yosef discovered what may be the earliest domestic camel bones yet found in Israel or even outside the Arabian Peninsula, dating to around 930 BC. This garnered considerable media coverage, as it is strong evidence that the stories of Abraham, Jacob, Esau, and Joseph were written after this time.
The existence of camels in Mesopotamia—but not in the eastern Mediterranean lands—is not a new idea. The historian Richard Bulliet did not think that the occasional mention of camels in the Bible meant that the domestic camels were common in the Holy Land at that time. The archaeologist William F. Albright, writing even earlier, saw camels in the Bible as an anachronism.
The official report by Sapir-Hen and Ben-Joseph notes:
The introduction of the dromedary camel (Camelus dromedarius) as a pack animal to the southern Levant ... substantially facilitated trade across the vast deserts of Arabia, promoting both economic and social change (e.g., Kohler 1984; Borowski 1998: 112–116; Jasmin 2005). This ... has generated extensive discussion regarding the date of the earliest domestic camel in the southern Levant (and beyond) (e.g., Albright 1949: 207; Epstein 1971: 558–584; Bulliet 1975; Zarins 1989; Köhler-Rollefson 1993; Uerpmann and Uerpmann 2002; Jasmin 2005; 2006; Heide 2010; Rosen and Saidel 2010; Grigson 2012). Most scholars today agree that the dromedary was exploited as a pack animal sometime in the early Iron Age (not before the 12th century [BC])
and concludes:
Current data from copper smelting sites of the Aravah Valley enable us to pinpoint the introduction of domestic camels to the southern Levant more precisely based on stratigraphic contexts associated with an extensive suite of radiocarbon dates. The data indicate that this event occurred not earlier than the last third of the 10th century [BC] and most probably during this time. The coincidence of this event with a major reorganization of the copper industry of the region—attributed to the results of the campaign of Pharaoh Shoshenq I—raises the possibility that the two were connected, and that camels were introduced as part of the efforts to improve efficiency by facilitating trade.
Textiles
Main article: Camel hair
Desert tribes and Mongolian nomads use camel hair for tents, yurts, clothing, bedding and accessories. Camels have outer guard hairs and soft inner down, and the fibers are sorted by color and age of the animal. The guard hairs can be felted for use as waterproof coats for the herdsmen, while the softer hair is used for premium goods. The fiber can be spun for use in weaving or made into yarns for hand knitting or crochet. Pure camel hair is recorded as being used for western garments from the 17th century onwards, and from the 19th century a mixture of wool and camel hair was used.
Military uses
Main article: Camel cavalry
By at least 1200 BC the first camel saddles had appeared, and Bactrian camels could be ridden. The first saddle was positioned to the back of the camel, and control of the Bactrian camel was exercised by means of a stick. However, between 500 and 100 BC, Bactrian camels came into military use. New saddles, which were inflexible and bent, were put over the humps and divided the rider's weight over the animal. In the seventh century BC the military Arabian saddle evolved, which again improved the saddle design slightly.
Military forces have used camel cavalries in wars throughout Africa, the Middle East, and into the modern-day Border Security Force (BSF) of India (though as of July 2012, the BSF planned the replacement of camels with ATVs). The first documented use of camel cavalries occurred in the Battle of Qarqar in 853 BC. Armies have also used camels as freight animals instead of horses and mules.
The East Roman Empire used auxiliary forces known as dromedarii, whom the Romans recruited in desert provinces. The camels were used mostly in combat because of their ability to scare off horses at close range (horses are afraid of the camels' scent), a quality famously employed by the Achaemenid Persians when fighting Lydia in the Battle of Thymbra (547 BC).
19th and 20th centuries
A photo of Bulgarian military-transport camels in 1912
A camel caravan of the Bulgarian military during the First Balkan War, 1912
The United States Army established the U.S. Camel Corps, stationed in California, in the 19th century.[19] One may still see stables at the Benicia Arsenal in Benicia, California, where they nowadays serve as the Benicia Historical Museum. Though the experimental use of camels was seen as a success (John B. Floyd, Secretary of War in 1858, recommended that funds be allocated towards obtaining a thousand more camels), the outbreak of the American Civil War in 1861 saw the end of the Camel Corps: Texas became part of the Confederacy, and most of the camels were left to wander away into the desert.
France created a méhariste camel corps in 1912 as part of the Armée d'Afrique in the Sahara in order to exercise greater control over the camel-riding Tuareg and Arab insurgents, as previous efforts to defeat them on foot had failed. The Free French Camel Corps fought during World War II, and camel-mounted units remained in service until the end of French rule over Algeria in 1962.
In 1916, the British created the Imperial Camel Corps. It was originally used to fight the Senussi, but was later used in the Sinai and Palestine Campaign in World War I. The Imperial Camel Corps comprised infantrymen mounted on camels for movement across desert, though they dismounted at battle sites and fought on foot. After July 1918, the Corps began to become run down, receiving no new reinforcements, and was formally disbanded in 1919.
In World War I, the British Army also created the Egyptian Camel Transport Corps, which consisted of a group of Egyptian camel drivers and their camels. The Corps supported British war operations in Sinai, Palestine, and Syria by transporting supplies to the troops.
The Somaliland Camel Corps was created by colonial authorities in British Somaliland in 1912; it was disbanded in 1944.
Bactrian camels were used by Romanian forces during World War II in the Caucasian region. At the same period the Soviet units operating around Astrakhan in 1942 adopted local camels as draft animals due to shortage of trucks and horses, and kept them even after moving out of the area. Despite severe losses, some of these camels ended up as far west as to Berlin itself.
The Bikaner Camel Corps of British India fought alongside the British Indian Army in World Wars I and II.
The Tropas Nómadas (Nomad Troops) were an auxiliary regiment of Sahrawi tribesmen serving in the colonial army in Spanish Sahara (today Western Sahara). Operational from the 1930s until the end of the Spanish presence in the territory in 1975, the Tropas Nómadas were equipped with small arms and led by Spanish officers. The unit guarded outposts and sometimes conducted patrols on camelback.
21st century competition
At the King Abdulaziz Camel Festival, in Saudi Arabia, thousands of camels are paraded and are judged on their lips and humps. The festival also features camel racing and camel milk tasting and has combined prize money of $57m (£40m). In 2018, 12 camels were disqualified from the beauty contest after it was discovered their owners had tried to improve their camel's good looks with injections of botox, into the animals' lips, noses and jaws. In 2021 over 40 camels were disqualified for acts of tampering and deception in beautifying camels.
Food uses
Dairy
Main article: Camel milk
Camel milk is a staple food of desert nomad tribes and is sometimes considered a meal itself; a nomad can live on only camel milk for almost a month.
Camel milk can readily be made into yogurt, but can only be made into butter if it is soured first, churned, and a clarifying agent is then added. Until recently, camel milk could not be made into camel cheese because rennet was unable to coagulate the milk proteins to allow the collection of curds. Developing less wasteful uses of the milk, the FAO commissioned Professor J.P. Ramet of the École Nationale Supérieure d'Agronomie et des Industries Alimentaires, who was able to produce curdling by the addition of calcium phosphate and vegetable rennet in the 1990s. The cheese produced from this process has low levels of cholesterol and is easy to digest, even for the lactose intolerant.
Camels provide food in the form of meat and milk. Approximately 3.3 million camels and camelids are slaughtered each year for meat worldwide. A camel carcass can provide a substantial amount of meat. The male dromedary carcass can weigh 300–400 kg (661–882 lb), while the carcass of a male Bactrian can weigh up to 650 kg (1,433 lb). The carcass of a female dromedary weighs less than the male, ranging between 250 and 350 kg (550 and 770 lb). The brisket, ribs and loin are among the preferred parts, and the hump is considered a delicacy. The hump contains "white and sickly fat", which can be used to make the khli (preserved meat) of mutton, beef, or camel. On the other hand, camel milk and meat are rich in protein, vitamins, glycogen, and other nutrients making them essential in the diet of many people. From chemical composition to meat quality, the dromedary camel is the preferred breed for meat production. It does well even in arid areas due to its unusual physiological behaviors and characteristics, which include tolerance to extreme temperatures, radiation from the sun, water paucity, rugged landscape and low vegetation. Camel meat is reported to taste like coarse beef, but older camels can prove to be very tough, although camel meat becomes tenderer the more it is cooked.
Camel is one of the animals that can be ritually slaughtered and divided into three portions (one for the home, one for extended family/social networks, and one for those who cannot afford to slaughter an animal themselves) for the qurban of Eid al-Adha.
The Abu Dhabi Officers' Club serves a camel burger mixed with beef or lamb fat in order to improve the texture and taste. In Karachi, Pakistan, some restaurants prepare nihari from camel meat. Specialist camel butchers provide expert cuts, with the hump considered the most popular.
Camel meat has been eaten for centuries. It has been recorded by ancient Greek writers as an available dish at banquets in ancient Persia, usually roasted whole. The Roman emperor Heliogabalus enjoyed camel's heel. Camel meat is mainly eaten in certain regions, including Eritrea, Somalia, Djibouti, Saudi Arabia, Egypt, Syria, Libya, Sudan, Ethiopia, Kazakhstan, and other arid regions where alternative forms of protein may be limited or where camel meat has had a long cultural history. Camel blood is also consumable, as is the case among pastoralists in northern Kenya, where camel blood is drunk with milk and acts as a key source of iron, vitamin D, salts and minerals.
A 2005 report issued jointly by the Saudi Ministry of Health and the United States Centers for Disease Control and Prevention details four cases of human bubonic plague resulting from the ingestion of raw camel liver.
Australia
Camel meat is also occasionally found in Australian cuisine: for example, a camel lasagna is available in Alice Springs. Australia has exported camel meat, primarily to the Middle East but also to Europe and the US, for many years. The meat is very popular among East African Australians, such as Somalis, and other Australians have also been buying it. The feral nature of the animals means they produce a different type of meat to farmed camels in other parts of the world, and it is sought after because it is disease-free, and a unique genetic group. Demand is outstripping supply, and governments are being urged not to cull the camels, but redirect the cost of the cull into developing the market. Australia has seven camel dairies, which produce milk, cheese and skincare products in addition to meat.
Religion
Islam
Main article: Animals in Islam
Muslims consider camel meat halal (Arabic: حلال, 'allowed'). However, according to some Islamic schools of thought, a state of impurity is brought on by the consumption of it. Consequently, these schools hold that Muslims must perform wudhu (ablution) before the next time they pray after eating camel meat. Also, some Islamic schools of thought consider it haram (Arabic: حرام, 'forbidden') for a Muslim to perform Salat in places where camels lie, as it is said to be a dwelling place of the Shaytan (Arabic: شيطان, 'Devil'). According to Abu Yusuf (d.798), the urine of camel may be used for medical treatment if necessary, but according to Abū Ḥanīfah, the drinking of camel urine is discouraged.
The Islamic texts contain several stories featuring camels. In the story of the people of Thamud, the prophet Salih miraculously brings forth a naqat (Arabic: ناقة, 'milch-camel') out of a rock. After the prophet Muhammad migrated from Mecca to Medina, he allowed his she-camel to roam there; the location where the camel stopped to rest determined the location where he would build his house in Medina.
Judaism
See also: Food and drink prohibitions
According to Jewish tradition, camel meat and milk are not kosher. Camels possess only one of the two kosher criteria; although they chew their cud, they do not possess cloven hooves: "But these you shall not eat among those that bring up the cud and those that have a cloven hoof: the camel, because it brings up its cud, but does not have a [completely] cloven hoof; it is unclean for you."
Cultural depictions
What may be the oldest carvings of camels were discovered in 2018 in Saudi Arabia. They were analysed by researchers from several scientific disciplines and, in 2021, were estimated to be 7,000 to 8,000 years old. The dating of rock art is made difficult by the lack of organic material in the carvings that may be tested, so the researchers attempting to date them tested animal bones found associated with the carvings, assessed erosion patterns, and analysed tool marks in order to determine a correct date for the creation of the sculptures. This Neolithic dating would make the carvings significantly older than Stonehenge (5,000 years old) and the Egyptian pyramids at Giza (4,500 years old) and it predates estimates for the domestication of camels.
Distribution and numbers
A view into a canyon: many camels gathering around a watering hole
Camels in the Guelta d'Archei, in northeastern Chad
There are approximately 14 million camels alive as of 2010, with 90% being dromedaries. Dromedaries alive today are domesticated animals (mostly living in the Horn of Africa, the Sahel, Maghreb, Middle East and South Asia). The Horn region alone has the largest concentration of camels in the world, where the dromedaries constitute an important part of local nomadic life. They provide nomadic people in Somalia and Ethiopia with milk, food, and transportation.
Over one million dromedary camels are estimated to be feral in Australia, descended from those introduced as a method of transport in the 19th and early 20th centuries. This population is growing about 8% per year; it was estimated at around 700,000 in 2008. Representatives of the Australian government have culled more than 100,000 of the animals in part because the camels use too much of the limited resources needed by sheep farmers.
A small population of introduced camels, dromedaries and Bactrians, wandered through Southwestern United States after having been imported in the 19th century as part of the U.S. Camel Corps experiment. When the project ended, they were used as draft animals in mines and escaped or were released. Twenty-five U.S. camels were bought and exported to Canada during the Cariboo Gold Rush.
The Bactrian camel is, as of 2010, reduced to an estimated 1.4 million animals, most of which are domesticated. The Wild Bactrian camel is a separate species and is the only truly wild (as opposed to feral) camel in the world. The wild camels are critically endangered and number approximately 1400, inhabiting the Gobi and Taklamakan Deserts in China and Mongolia.
A camel (from Latin: camelus and Greek: κάμηλος (kamēlos) from Ancient Semitic: gāmāl) is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provide food (milk and meat) and textiles (fiber and felt from hair). Camels are working animals especially suited to their desert habitat and are a vital means of transport for passengers and cargo. There are three surviving species of camel. The one-humped dromedary makes up 94% of the world's camel population, and the two-humped Bactrian camel makes up 6%. The wild Bactrian camel is a separate species and is now critically endangered.
The word camel is also used informally in a wider sense, where the more correct term is "camelid", to include all seven species of the family Camelidae: the true camels (the above three species), along with the "New World" camelids: the llama, the alpaca, the guanaco, and the vicuña, which belong to the separate tribe Lamini. Camelids originated in North America during the Eocene, with the ancestor of modern camels, Paracamelus, migrating across the Bering land bridge into Asia during the late Miocene, around 6 million years ago.
Taxonomy
Extant species
Three species are extant:
ImageCommon nameScientific nameDistribution
Bactrian camelCamelus bactrianusDomesticated; Central Asia, including the historical region of Bactria.
Dromedary / Arabian camelCamelus dromedariusDomesticated; the Middle East, Sahara Desert, and South Asia; introduced to Australia
Wild Bactrian camelCamelus ferusRemote areas of northwest China and Mongolia
Biology
The average life expectancy of a camel is 40 to 50 years. A full-grown adult dromedary camel stands 1.85 m (6 ft 1 in) at the shoulder and 2.15 m (7 ft 1 in) at the hump. Bactrian camels can be a foot taller. Camels can run at up to 65 km/h (40 mph) in short bursts and sustain speeds of up to 40 km/h (25 mph). Bactrian camels weigh 300 to 1,000 kg (660 to 2,200 lb) and dromedaries 300 to 600 kg (660 to 1,320 lb). The widening toes on a camel's hoof provide supplemental grip for varying soil sediments.
The male dromedary camel has an organ called a dulla in his throat, a large, inflatable sac that he extrudes from his mouth when in rut to assert dominance and attract females. It resembles a long, swollen, pink tongue hanging out of the side of the camel's mouth. Camels mate by having both male and female sitting on the ground, with the male mounting from behind. The male usually ejaculates three or four times within a single mating session. Camelids are the only ungulates to mate in a sitting position.
Ecological and behavioral adaptations
Camel humps store fat, which are used as nourishment when food is scarce. If a camel uses the fat inside the hump, the hump will become limp and droop down
Camels do not directly store water in their humps; they are reservoirs of fatty tissue. When this tissue is metabolized, it yields a greater mass of water than that of the fat processed. This fat metabolization, while releasing energy, causes water to evaporate from the lungs during respiration (as oxygen is required for the metabolic process): overall, there is a net decrease in water.
Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water. The dromedary camel can drink as seldom as once every 10 days even under very hot conditions, and can lose up to 30% of its body mass due to dehydration. Unlike other mammals, camels' red blood cells are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: a 600 kg (1,300 lb) camel can drink 200 L (53 US gal) of water in three minutes.
Camels are able to withstand changes in body temperature and water consumption that would kill most other mammals. Their temperature ranges from 34 °C (93 °F) at dawn and steadily increases to 40 °C (104 °F) by sunset, before they cool off at night again. In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day. Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a rete mirabile, a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain. Camels rarely sweat, even when ambient temperatures reach 49 °C (120 °F). Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight in water, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance.
When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water. Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.
Domesticated camel calves lying in sternal recumbency, a position that aids heat loss
The camel's thick coat insulates it from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating. During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn. The camel's long legs help by keeping its body farther from the ground, which can heat up to 70 °C (158 °F). Dromedaries have a pad of thick tissue over the sternum called the pedestal. When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body.
Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their translucent third eyelid (also known as the nictitating membrane). The camels' gait and widened feet help them move without sinking into the sand.
The kidneys and intestines of a camel are very efficient at reabsorbing water. Camels' kidneys have a 1:4 cortex to medulla ratio. Thus, the medullary part of a camel's kidney occupies twice as much area as a cow's kidney. Secondly, renal corpuscles have a smaller diameter, which reduces surface area for filtration. These two major anatomical characteristics enable camels to conserve water and limit the volume of urine in extreme desert conditions. Camel urine comes out as a thick syrup, and camel faeces are so dry that they do not require drying when used to fuel fires.
The camel immune system differs from those of other mammals. Normally, the Y-shaped antibody molecules consist of two heavy (or long) chains along the length of the Y, and two light (or short) chains at each tip of the Y. Camels, in addition to these, also have antibodies made of only two heavy chains, a trait that makes them smaller and more durable. These "heavy-chain-only" antibodies, discovered in 1993, are thought to have developed 50 million years ago, after camelids split from ruminants and pigs. Camels suffer from surra caused by Trypanosoma evansi wherever camels are domesticated in the world: 2 and resultantly camels have evolved trypanolytic antibodies as with many mammals. In the future, nanobody/single-domain antibody therapy will surpass natural camel antibodies by reaching locations currently unreachable due to natural antibodies' larger size.: 788 Such therapies may also be suitable for other mammals.: 788 Tran et al. 2009 provides a new reference test for surra (T. evansi) of camel. They use recombinant Invariant Surface Glycoprotein 75 (rISG75, an Invariant Surface Glycoprotein) and ELISA. The Tran test has high test specificity and appears likely to work just as well for T. evansi in other hosts, and for a pan-Trypanozoon test, which would also be useful for T. b. brucei, T. b. gambiense, T. b. rhodesiense, and T. equiperdum.
Genetics
The karyotypes of different camelid species have been studied earlier by many groups, but no agreement on chromosome nomenclature of camelids has been reached. A 2007 study flow sorted camel chromosomes, building on the fact that camels have 37 pairs of chromosomes (2n=74), and found that the karyotype consisted of one metacentric, three submetacentric, and 32 acrocentric autosomes. The Y is a small metacentric chromosome, while the X is a large metacentric chromosome.
The hybrid camel, a hybrid between Bactrian and dromedary camels, has one hump, though it has an indentation 4–12 cm (1.6–4.7 in) deep that divides the front from the back. The hybrid is 2.15 m (7 ft 1 in) at the shoulder and 2.32 m (7 ft 7 in) tall at the hump. It weighs an average of 650 kg (1,430 lb) and can carry around 400 to 450 kg (880 to 990 lb), which is more than either the dromedary or Bactrian can.
According to molecular data, the wild Bactrian camel (C. ferus) separated from the domestic Bactrian camel (C. bactrianus) about 1 million years ago. New World and Old World camelids diverged about 11 million years ago. In spite of this, these species can hybridize and produce viable offspring. The cama is a camel-llama hybrid bred by scientists to see how closely related the parent species are. Scientists collected semen from a camel via an artificial vagina and inseminated a llama after stimulating ovulation with gonadotrophin injections. The cama is halfway in size between a camel and a llama and lacks a hump. It has ears intermediate between those of camels and llamas, longer legs than the llama, and partially cloven hooves. Like the mule, camas are sterile, despite both parents having the same number of chromosomes.
Evolution
The earliest known camel, called Protylopus, lived in North America 40 to 50 million years ago (during the Eocene). It was about the size of a rabbit and lived in the open woodlands of what is now South Dakota. By 35 million years ago, the Poebrotherium was the size of a goat and had many more traits similar to camels and llamas. The hoofed Stenomylus, which walked on the tips of its toes, also existed around this time, and the long-necked Aepycamelus evolved in the Miocene. The split between the tribes Camelini, which contains modern camels and Lamini, modern llamas, alpacas, vicuñas, and guanacos, is estimated to have occurred over 16 million years ago.
The ancestor of modern camels, Paracamelus, migrated into Eurasia from North America via Beringia during the late Miocene, between 7.5 and 6.5 million years ago. During the Pleistocene, around 3 to 1 million years ago, the North American Camelidae spread to South America as part of the Great American Interchange via the newly formed Isthmus of Panama, where they gave rise to guanacos and related animals. Populations of Paracamelus continued to exist in the North American Arctic into the Early Pleistocene. This creature is estimated to have stood around nine feet (2.7 metres) tall. The Bactrian camel diverged from the dromedary about 1 million years ago, according to the fossil record.
The last camel native to North America was Camelops hesternus, which vanished along with horses, short-faced bears, mammoths and mastodons, ground sloths, sabertooth cats, and many other megafauna as part of the Quaternary extinction event, coinciding with the migration of humans from Asia at the end of the Pleistocene, around 13–11,000 years ago.
Domestication
Like horses, camels originated in North America and eventually spread across Beringia to Asia. They survived in the Old World, and eventually humans domesticated them and spread them globally. Along with many other megafauna in North America, the original wild camels were wiped out during the spread of the first indigenous peoples of the Americas from Asia into North America, 10 to 12,000 years ago; although fossils have never been associated with definitive evidence of hunting.
Most camels surviving today are domesticated. Although feral populations exist in Australia, India and Kazakhstan, wild camels survive only in the wild Bactrian camel population of the Gobi Desert.
History
When humans first domesticated camels is disputed. Dromedaries may have first been domesticated by humans in Somalia or South Arabia sometime during the 3rd millennium BC, the Bactrian in central Asia around 2,500 BC, as at Shar-i Sokhta (also known as the Burnt City), Iran. A study from 2016, which genotyped and used world-wide sequencing of modern and ancient mitochondrial DNA (mtDNA), suggested that they were initially domesticated in the southeast Arabian Peninsula, with the Bactrian type later being domesticated around Central Asia.
Martin Heide's 2010 work on the domestication of the camel tentatively concludes that humans had domesticated the Bactrian camel by at least the middle of the third millennium somewhere east of the Zagros Mountains, with the practice then moving into Mesopotamia. Heide suggests that mentions of camels "in the patriarchal narratives may refer, at least in some places, to the Bactrian camel", while noting that the camel is not mentioned in relationship to Canaan. Heide and Joris Peters reasserted that conclusion in their 2021 study on the subject.
In 2009-2013, excavations in the Timna Valley by Lidar Sapir-Hen and Erez Ben-Yosef discovered what may be the earliest domestic camel bones yet found in Israel or even outside the Arabian Peninsula, dating to around 930 BC. This garnered considerable media coverage, as it is strong evidence that the stories of Abraham, Jacob, Esau, and Joseph were written after this time.
The existence of camels in Mesopotamia—but not in the eastern Mediterranean lands—is not a new idea. The historian Richard Bulliet did not think that the occasional mention of camels in the Bible meant that the domestic camels were common in the Holy Land at that time. The archaeologist William F. Albright, writing even earlier, saw camels in the Bible as an anachronism.
The official report by Sapir-Hen and Ben-Joseph notes:
The introduction of the dromedary camel (Camelus dromedarius) as a pack animal to the southern Levant ... substantially facilitated trade across the vast deserts of Arabia, promoting both economic and social change (e.g., Kohler 1984; Borowski 1998: 112–116; Jasmin 2005). This ... has generated extensive discussion regarding the date of the earliest domestic camel in the southern Levant (and beyond) (e.g., Albright 1949: 207; Epstein 1971: 558–584; Bulliet 1975; Zarins 1989; Köhler-Rollefson 1993; Uerpmann and Uerpmann 2002; Jasmin 2005; 2006; Heide 2010; Rosen and Saidel 2010; Grigson 2012). Most scholars today agree that the dromedary was exploited as a pack animal sometime in the early Iron Age (not before the 12th century [BC])
and concludes:
Current data from copper smelting sites of the Aravah Valley enable us to pinpoint the introduction of domestic camels to the southern Levant more precisely based on stratigraphic contexts associated with an extensive suite of radiocarbon dates. The data indicate that this event occurred not earlier than the last third of the 10th century [BC] and most probably during this time. The coincidence of this event with a major reorganization of the copper industry of the region—attributed to the results of the campaign of Pharaoh Shoshenq I—raises the possibility that the two were connected, and that camels were introduced as part of the efforts to improve efficiency by facilitating trade.
Textiles
Main article: Camel hair
Desert tribes and Mongolian nomads use camel hair for tents, yurts, clothing, bedding and accessories. Camels have outer guard hairs and soft inner down, and the fibers are sorted by color and age of the animal. The guard hairs can be felted for use as waterproof coats for the herdsmen, while the softer hair is used for premium goods. The fiber can be spun for use in weaving or made into yarns for hand knitting or crochet. Pure camel hair is recorded as being used for western garments from the 17th century onwards, and from the 19th century a mixture of wool and camel hair was used.
Military uses
Main article: Camel cavalry
By at least 1200 BC the first camel saddles had appeared, and Bactrian camels could be ridden. The first saddle was positioned to the back of the camel, and control of the Bactrian camel was exercised by means of a stick. However, between 500 and 100 BC, Bactrian camels came into military use. New saddles, which were inflexible and bent, were put over the humps and divided the rider's weight over the animal. In the seventh century BC the military Arabian saddle evolved, which again improved the saddle design slightly.
Military forces have used camel cavalries in wars throughout Africa, the Middle East, and into the modern-day Border Security Force (BSF) of India (though as of July 2012, the BSF planned the replacement of camels with ATVs). The first documented use of camel cavalries occurred in the Battle of Qarqar in 853 BC. Armies have also used camels as freight animals instead of horses and mules.
The East Roman Empire used auxiliary forces known as dromedarii, whom the Romans recruited in desert provinces. The camels were used mostly in combat because of their ability to scare off horses at close range (horses are afraid of the camels' scent), a quality famously employed by the Achaemenid Persians when fighting Lydia in the Battle of Thymbra (547 BC).
19th and 20th centuries
A photo of Bulgarian military-transport camels in 1912
A camel caravan of the Bulgarian military during the First Balkan War, 1912
The United States Army established the U.S. Camel Corps, stationed in California, in the 19th century.[19] One may still see stables at the Benicia Arsenal in Benicia, California, where they nowadays serve as the Benicia Historical Museum. Though the experimental use of camels was seen as a success (John B. Floyd, Secretary of War in 1858, recommended that funds be allocated towards obtaining a thousand more camels), the outbreak of the American Civil War in 1861 saw the end of the Camel Corps: Texas became part of the Confederacy, and most of the camels were left to wander away into the desert.
France created a méhariste camel corps in 1912 as part of the Armée d'Afrique in the Sahara in order to exercise greater control over the camel-riding Tuareg and Arab insurgents, as previous efforts to defeat them on foot had failed. The Free French Camel Corps fought during World War II, and camel-mounted units remained in service until the end of French rule over Algeria in 1962.
In 1916, the British created the Imperial Camel Corps. It was originally used to fight the Senussi, but was later used in the Sinai and Palestine Campaign in World War I. The Imperial Camel Corps comprised infantrymen mounted on camels for movement across desert, though they dismounted at battle sites and fought on foot. After July 1918, the Corps began to become run down, receiving no new reinforcements, and was formally disbanded in 1919.
In World War I, the British Army also created the Egyptian Camel Transport Corps, which consisted of a group of Egyptian camel drivers and their camels. The Corps supported British war operations in Sinai, Palestine, and Syria by transporting supplies to the troops.
The Somaliland Camel Corps was created by colonial authorities in British Somaliland in 1912; it was disbanded in 1944.
Bactrian camels were used by Romanian forces during World War II in the Caucasian region. At the same period the Soviet units operating around Astrakhan in 1942 adopted local camels as draft animals due to shortage of trucks and horses, and kept them even after moving out of the area. Despite severe losses, some of these camels ended up as far west as to Berlin itself.
The Bikaner Camel Corps of British India fought alongside the British Indian Army in World Wars I and II.
The Tropas Nómadas (Nomad Troops) were an auxiliary regiment of Sahrawi tribesmen serving in the colonial army in Spanish Sahara (today Western Sahara). Operational from the 1930s until the end of the Spanish presence in the territory in 1975, the Tropas Nómadas were equipped with small arms and led by Spanish officers. The unit guarded outposts and sometimes conducted patrols on camelback.
21st century competition
At the King Abdulaziz Camel Festival, in Saudi Arabia, thousands of camels are paraded and are judged on their lips and humps. The festival also features camel racing and camel milk tasting and has combined prize money of $57m (£40m). In 2018, 12 camels were disqualified from the beauty contest after it was discovered their owners had tried to improve their camel's good looks with injections of botox, into the animals' lips, noses and jaws. In 2021 over 40 camels were disqualified for acts of tampering and deception in beautifying camels.
Food uses
Dairy
Main article: Camel milk
Camel milk is a staple food of desert nomad tribes and is sometimes considered a meal itself; a nomad can live on only camel milk for almost a month.
Camel milk can readily be made into yogurt, but can only be made into butter if it is soured first, churned, and a clarifying agent is then added. Until recently, camel milk could not be made into camel cheese because rennet was unable to coagulate the milk proteins to allow the collection of curds. Developing less wasteful uses of the milk, the FAO commissioned Professor J.P. Ramet of the École Nationale Supérieure d'Agronomie et des Industries Alimentaires, who was able to produce curdling by the addition of calcium phosphate and vegetable rennet in the 1990s. The cheese produced from this process has low levels of cholesterol and is easy to digest, even for the lactose intolerant.
Camels provide food in the form of meat and milk. Approximately 3.3 million camels and camelids are slaughtered each year for meat worldwide. A camel carcass can provide a substantial amount of meat. The male dromedary carcass can weigh 300–400 kg (661–882 lb), while the carcass of a male Bactrian can weigh up to 650 kg (1,433 lb). The carcass of a female dromedary weighs less than the male, ranging between 250 and 350 kg (550 and 770 lb). The brisket, ribs and loin are among the preferred parts, and the hump is considered a delicacy. The hump contains "white and sickly fat", which can be used to make the khli (preserved meat) of mutton, beef, or camel. On the other hand, camel milk and meat are rich in protein, vitamins, glycogen, and other nutrients making them essential in the diet of many people. From chemical composition to meat quality, the dromedary camel is the preferred breed for meat production. It does well even in arid areas due to its unusual physiological behaviors and characteristics, which include tolerance to extreme temperatures, radiation from the sun, water paucity, rugged landscape and low vegetation. Camel meat is reported to taste like coarse beef, but older camels can prove to be very tough, although camel meat becomes tenderer the more it is cooked.
Camel is one of the animals that can be ritually slaughtered and divided into three portions (one for the home, one for extended family/social networks, and one for those who cannot afford to slaughter an animal themselves) for the qurban of Eid al-Adha.
The Abu Dhabi Officers' Club serves a camel burger mixed with beef or lamb fat in order to improve the texture and taste. In Karachi, Pakistan, some restaurants prepare nihari from camel meat. Specialist camel butchers provide expert cuts, with the hump considered the most popular.
Camel meat has been eaten for centuries. It has been recorded by ancient Greek writers as an available dish at banquets in ancient Persia, usually roasted whole. The Roman emperor Heliogabalus enjoyed camel's heel. Camel meat is mainly eaten in certain regions, including Eritrea, Somalia, Djibouti, Saudi Arabia, Egypt, Syria, Libya, Sudan, Ethiopia, Kazakhstan, and other arid regions where alternative forms of protein may be limited or where camel meat has had a long cultural history. Camel blood is also consumable, as is the case among pastoralists in northern Kenya, where camel blood is drunk with milk and acts as a key source of iron, vitamin D, salts and minerals.
A 2005 report issued jointly by the Saudi Ministry of Health and the United States Centers for Disease Control and Prevention details four cases of human bubonic plague resulting from the ingestion of raw camel liver.
Australia
Camel meat is also occasionally found in Australian cuisine: for example, a camel lasagna is available in Alice Springs. Australia has exported camel meat, primarily to the Middle East but also to Europe and the US, for many years. The meat is very popular among East African Australians, such as Somalis, and other Australians have also been buying it. The feral nature of the animals means they produce a different type of meat to farmed camels in other parts of the world, and it is sought after because it is disease-free, and a unique genetic group. Demand is outstripping supply, and governments are being urged not to cull the camels, but redirect the cost of the cull into developing the market. Australia has seven camel dairies, which produce milk, cheese and skincare products in addition to meat.
Religion
Islam
Main article: Animals in Islam
Muslims consider camel meat halal (Arabic: حلال, 'allowed'). However, according to some Islamic schools of thought, a state of impurity is brought on by the consumption of it. Consequently, these schools hold that Muslims must perform wudhu (ablution) before the next time they pray after eating camel meat. Also, some Islamic schools of thought consider it haram (Arabic: حرام, 'forbidden') for a Muslim to perform Salat in places where camels lie, as it is said to be a dwelling place of the Shaytan (Arabic: شيطان, 'Devil'). According to Abu Yusuf (d.798), the urine of camel may be used for medical treatment if necessary, but according to Abū Ḥanīfah, the drinking of camel urine is discouraged.
The Islamic texts contain several stories featuring camels. In the story of the people of Thamud, the prophet Salih miraculously brings forth a naqat (Arabic: ناقة, 'milch-camel') out of a rock. After the prophet Muhammad migrated from Mecca to Medina, he allowed his she-camel to roam there; the location where the camel stopped to rest determined the location where he would build his house in Medina.
Judaism
See also: Food and drink prohibitions
According to Jewish tradition, camel meat and milk are not kosher. Camels possess only one of the two kosher criteria; although they chew their cud, they do not possess cloven hooves: "But these you shall not eat among those that bring up the cud and those that have a cloven hoof: the camel, because it brings up its cud, but does not have a [completely] cloven hoof; it is unclean for you."
Cultural depictions
What may be the oldest carvings of camels were discovered in 2018 in Saudi Arabia. They were analysed by researchers from several scientific disciplines and, in 2021, were estimated to be 7,000 to 8,000 years old. The dating of rock art is made difficult by the lack of organic material in the carvings that may be tested, so the researchers attempting to date them tested animal bones found associated with the carvings, assessed erosion patterns, and analysed tool marks in order to determine a correct date for the creation of the sculptures. This Neolithic dating would make the carvings significantly older than Stonehenge (5,000 years old) and the Egyptian pyramids at Giza (4,500 years old) and it predates estimates for the domestication of camels.
Distribution and numbers
A view into a canyon: many camels gathering around a watering hole
Camels in the Guelta d'Archei, in northeastern Chad
There are approximately 14 million camels alive as of 2010, with 90% being dromedaries. Dromedaries alive today are domesticated animals (mostly living in the Horn of Africa, the Sahel, Maghreb, Middle East and South Asia). The Horn region alone has the largest concentration of camels in the world, where the dromedaries constitute an important part of local nomadic life. They provide nomadic people in Somalia and Ethiopia with milk, food, and transportation.
Over one million dromedary camels are estimated to be feral in Australia, descended from those introduced as a method of transport in the 19th and early 20th centuries. This population is growing about 8% per year; it was estimated at around 700,000 in 2008. Representatives of the Australian government have culled more than 100,000 of the animals in part because the camels use too much of the limited resources needed by sheep farmers.
A small population of introduced camels, dromedaries and Bactrians, wandered through Southwestern United States after having been imported in the 19th century as part of the U.S. Camel Corps experiment. When the project ended, they were used as draft animals in mines and escaped or were released. Twenty-five U.S. camels were bought and exported to Canada during the Cariboo Gold Rush.
The Bactrian camel is, as of 2010, reduced to an estimated 1.4 million animals, most of which are domesticated. The Wild Bactrian camel is a separate species and is the only truly wild (as opposed to feral) camel in the world. The wild camels are critically endangered and number approximately 1400, inhabiting the Gobi and Taklamakan Deserts in China and Mongolia.
I have found a handful of withering syndrome black abalone in the last year or so. I know that WS does affect other species and a few of you have shared some images of red abalone with WS recently. Back when I worked at the DCPP Bio Lab, we would find reds in the tanks pretty commonly showing WS symptoms. Here are images of the first red abalone showing WS symptoms I have personally found in the wild.
Withering Syndrome of Abalone: from (www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/fwsab...)
Common, generally accepted names of the organism or disease agent
Withering syndrome (WS), Withering disease, Foot withering syndrome, Abalone wasting disease, Withering syndrome - an intracellular Rickettsiales-like prokaryote (WS-RLP).
Scientific name or taxonomic affiliation
'Candidatus Xenohaliotis californiensis', a proposed new genus and new species of intracellular prokaryote, with morphological characteristics of the class Proteobacteria, order Rickettsiales and family Rickettsiaceae, in the epithelium of the intestinal tract (Gardner et al. 1995, Friedman et al. 2000b to d). Initially, heavy infections of coccidia in the kidney were thought to cause the disease but, a correlation between coccidial infection and withering syndrome was not found (Steinbeck et al. 1992; VanBlaricom et al. 1993; Kuris et al. 1994; Friedman et al. 1997).
Geographic distribution
Coast of California, USA, south of Point Conception and on the west coast of Baja California, Mexico. In Diablo Cove, California (70 km north of Point Conception), disease and mortalities were limited to the immediate vicinity of a warm-water discharge. In 1996, there was evidence that this disease was progressing northward from Point Conception (Altstatt et al. 1996) and possibly as far north as San Francisco, California (Finley and Friedman 2000). In addition, the bacterium (but not withering syndrome) was detected at two locations in northern California (Crescent City and Van Damme) (Friedman and Finley 2003). In surveys of abalone from Baja California, Mexico, this pathogen was detected in high prevalences in the digestive tract of symptomatic and non-symptomatic cultured and natural populations of H. rufescens, H. fulgens and H. corrugata (Cáceres Martínez and Tinoco Orta 2000, Cáceres Martínez et al. 2000, Caceres-Martinez and Tinoco-Orta 2001, Álvarez-Tinajero et al. 2002). Recently, Xenohaliotis californiensis was reported in H. rufescens cultured in Iceland (unofficial report from Gisli Jonsson in an e-mail dated November 8, 2004) and in H. tuberculata cultured in Ireland in 2006 (records of the OIE) and France (Balserio et al. 2006) with no associated mortalities in these cases. However, H. tuberculata experimentally grown in Galicia (NW Spain) from stocks originating in Ireland experienced high mortality (45% to 100%) within 14 months of importation (most mortalities occurring during the spring and summer months) and were infected with X. californiensis but the associated mortalities were attributed to a co-infection with a protistan pathogen (Balserio et al. 2006).
A similar looking disease of unknown etiology has been reported from cultured Haliotis discus hannai on the northern coast of China (Guo et al. 1999). Rickettsia-like organisms have also been reported in the digestive tract of abalone (Haliotis midae) from culture facilities in South Africa with no associated pathology (Mouton 2000).
Host species
Disease most evident in Haliotis cracherodii, however, the disease and pathogen also occurs in Haliotis rufescens, Haliotis corrugata, Haliotis fulgens, Haliotis sorenseni and Haliotis tuberculata and possibly in Haliotis discus hannai and Haliotis midae.
Impact on the host
A lethal disease that affects all sizes of abalone and causes lethargy, retracted visceral tissues, atrophy of the foot muscle (thereby adversely affects the ability of the abalone to adhere to the substrate) and is lethal. Elevated temperatures accelerated disease progression and decreased survival. At 18 to 20 °C, death usually occurs within one month of the appearance of the clinical signs. Diseased abalone consumed 4.4 times less kelp, 1.2 times less oxygen and excreted 3.8 time more ammonia per gram wet weight than did healthy abalone (Kismohandaka et al. 1993). Severe metabolic alterations were detected in abalone before visible atrophy of the foot occurred. Haemocyanin concentration in the blood decreased, glycogen in the foot muscle was depleted, haemocyte abundance was reduced and haemocytes with abnormal morphology increased in wasted abalone (Friedman 1996; Shields et al. 1996). In addition, haemocytes were more chemotactically active but the capability of the stimulated cells to engulf and destroy foreign particles appeared to be compromised and may contribute to mortality associated with the disease (Friedman et al. 1999, 2000a). Mass specific ammonia excretion was observed in affected abalone indicating protein from the foot muscle was being used as an energy source. This conclusion was also suggested by Kismohandaka et al. (1995) who observed severe foot muscle fibre depletion in samples examined using histology. However, no pathogens were found in the muscle or blood tissues.
This disease is associated with mass mortalities of H. cracherodii. Withering syndrome progressively spread throughout the California Channel Islands causing population crashes on six of the eight Channel Islands by 1992 (95 to 100 percent of the H. cracherodii were lost) and closure of the California black abalone fishery in 1993. A dramatic increase in the number of cultured H. rufescens with foot withering syndrome was noticed in conjunction with El Niño - Southern Oscillation (ENSO) elevated seawater temperatures (Moore et al. 1999). However, differences in susceptibility and tissue changes were noted between species with H. cracherodii being more susceptible than H. rufescens and survivors appear to be relatively resistant to the disease (Friedman et al. 2003b).
Diagnostic techniques
Gross Observations: Body mass relative to shell size is smaller than normal. Affected abalone were discoloured (pale) and weakened, and the soft tissues were atrophied and non-responsive to stimuli. In the field, affected abalone can be detached from the substrate by hand and do not attempt to right themselves when turned upside down.
Squash Preparations: Minced pieces (about 2 mm square) of gastrointestinal tract from the posterior portion of the esophagus to the posterior end of the crop were places on a microscope slide, gently pressed into the slide with a second slide and dried with low heat from a blow dryer for 20 min. Dried samples can be prepared for examination immediately or held indefinitely at 4 °C with desiccant. To prepare for examination, the tissue was flooded with a 10 µg per ml solution of Hoechst 33258 (bisBenzimide, Sigma, St. Louis, MO, USA) in distilled water, covered with a coverslip, incubated in the dark for several minutes and viewed at 100 to 400X magnification with a epifluorescent ultraviolet light and filters appropriate for the spectra of 356 nm excitation and 465 nm emission. This staining technique caused the large inclusions of Xenohaliotis californiensis, which are usually difficult to detect in unstained tissue, to fluoresce a bright blue against a black to dull red background. Although the abalone cell nuclei were also fluorescent, they were small ( about 5 µm in length) in comparison to the inclusions (about 50 µm in length). An alternate nucleic acid-specific fluorochrome, propidium iodide (10 µg per ml in distilled water, Sigma), viewed with ultraviolet light and 530 nm excitation and 615 nm emission filters gave similar results (for further details see Moore et al. 2001a).
Histology: Severe foot muscle fiber depletion. Occurrence of extensive infections of Gram-negative intracellular prokaryotes in the epithelium of the intestinal tract, especially in the enzymes secreting cells of the digestive diverticula. The prokaryotes had morphological characteristics of the order Rickettsiales. They were accumulated into intracellular colonies within epithelial cells. Infection of the digestive diverticula is accompanied by a loss of digestive enzyme granules from epithelial cells and apparently by a metaplasia of enzyme secretory cells to cells morphologically similar to epithelial cells lining the gut (Gardner et al. 1995). This pathology in heavily infected abalone is speculated to be the cause of muscle tissue catabolism resulting in the withering disease.
Electron Microscopy: Observation of rod-shaped, ribosome-rich prokaryotes with trilaminar cell walls accumulated into intracellular colonies within membrane-bound vacuoles in the cytoplasm of gastrointestinal epithelial cells.
DNA Probes: The 16S rDNA was amplified, cloned and sequenced. A polymerase chain reaction (PCR) test was developed that specifically amplifies a 160 base-pair segment of the Rickettsia-like pathogen but not four other microbial species isolated from the gut of abalone. Apparently, this PCR test greatly increases the ability to detect the pathogen (Andree et al. 2000). Also, an in situ hybridization test has been developed (Antonio et al. 2000).
Methods of control
Experiments indicate that the pathogen can be transmitted via the water column and did not require direct contact between infected and uninfected abalone (Moore et al. 2000a and 2001b, Friedman et al. 2002). Above normal temperatures seem to have a synergistic effect on the disease (Cáceres Martínez et al. 2000, Moore et al. 2000a, Raimondi et al. 2002). Results of experiments by Friedman et al.(1997) and Moore et al. (2000a and b) indicated that H. cracherodii and H. rufescens, respectively, held at elevated temperatures (20 °C and 18.5 °C, respectively) had higher mortality, more severe signs of WS and more severe infections with the Rickettsia-like prokaryote than those held in cooler waters (13 °C and 14 °C, respectively). Also, the recovery of black abalone populations affected by mass mortalities from foot withering syndrome seemed to be closely linked with temperature. In affected culture facilities, the severity of the disease may be curtailed if water temperatures could be reduced to about 15 °C or less (Moore et al. 1999). Results of subsequent long-term (447 days) experimentation employing fed and starved abalone indicated that the high morbidity and mortality exhibited by infected abalone is a consequence of disease and not direct thermal stress (Braid et al. 2005).
Oceanographic factors that result in elevated seawater temperatures (i.e., ENSO) had a strong negative impact on the recovery of black abalone populations in southern California (Tissot 1995). These elevated temperatures were also associated with a dramatic increase in the number of red abalone with foot withering syndrome in culture facilities in California (Moore et al. 1999). Despite the devastation caused to black abalone populations, a few large, old individuals can still be found and some small juveniles have been seen (Haaker 1997). Also, the research of Tissot (1995) suggests that black abalone populations in southern California may recover with the subsidence of ENSO oceanographic conditions. Genetic structure of black abalone populations in the California islands and central California coast was assessed in order to identify patterns of recruitment in surviving populations (Chambers et al. 2006).
Evidence indicated that the occurrence of Xenohaliotis californiensis in H. rufescens at two new locations in northern California were associated with out-plants of hatchery-reared abalone, suggesting a link between restoration efforts and the present distribution of this pathogen (Friedman and Finley 2003). The detection of the pathogen outside the previous known distribution highlights the need for careful assessment of animal health before restocking depleted populations or transplanting animals for aquaculture.
Intramuscular injection and oral administration of an antibiotic was effective in reducing the losses of infected abalone (Friedman et al. 2003a) and tissue retention of this therapeutant in the digestive gland remained high for a prolonged time (at least 38 days post treatment) (Braid et al. 2005, Friedman et al. 2007). However, other antimicrobials had no measurable affect on the disease (Friedman et al. 2000b).
www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/fwsab...
Photo courtesy John McDonald/MacDonald.
New Orleans Hotel Hill Climb. [26km in to Stage]
#16 Michael McLister A Grade [Christchurch] won this climb and pocketed $25 while I picked up $15 for 2nd place up this climb. The field totaled 48 riders; 30 A Grade & 18 B Grade.
Stage 9 [quite a lot of short sharp hills/climbing] was the 3rd Stage held that Saturday 10 October 1987. Stage 7 began that day at 9am and went from Winton to Mossburn travelling through Benmore, Dipton, Lumsden and finishing in Mossburn at 11am [approx] a distance of 73km.
Stage 8 began at 12.20pm and started went from Five Rivers to Queenstown travelling through Garston, Kingston, Frankton, and finishing in Queenstown at 3.10pm [approx] a distance of 95km. I blew badly [bonked - glycogen depletion - I suffered from this several times during the 3 Tour Of Southand events I competed in. Admittedly I struggled with experience in large number scratch racing and at that level I struggled positioning myself sometimes leading in to hills] halfway through this stage and rode in late in to Queenstown.
It was very cold and my morale was crushed. I even considered pulling out of the race. However my manager Wayne McLellan [unfortunately had a tragic bike racing accident in Timaru where a car drove in to a bunch of competing riders at an intersection in 1986 - I was also in the race - and was in a coma for 3 weeks, miraculous story of survival itself] discussed what was happening and suggested I ride clear of the bunch a wee bit before a climb and that way the riders would pick me up say half way up and then it would just be a case of 'hanging on' to the top and I 'should be ok from there'. I followed his advice, however the complete peloton 'left me go' after I took off just after the start of Stage 9. So I thought I'd put the hammer down and kept going. Another rider from Christchurch Michael McLister was allowed to chase up to me, and the pair of us discussed the situation and agreed to work together and see if we could actually hold our breakaway. Our turns were equal however it was Michael McLister as seen in this excellent photo taken by John McDonald, who was definitely stronger than I was on hills. It was pointless for him to attempt to drop me as I was capable of catching him on flat terrain.
As we headed west in to Arrowtown from the turn left of Main Highway 6 in to McDonnell Road we began to believe we could actually win the Stage. I decided to throw in a couple of burner laps to test Michael's legs and to my dismay I wondered if there was a chink in his amour. I also made a decision to feign fatigue. It worked perfectly because by this point we were really flying along. We both began dreaming of victory. As we came down a slight descent in to the main street for the sprint to the finish line Michael must have felt very confident and began to lead out the sprint and I was delighted because I too rated my sprint. I clicked in to a big sprint gear I believed would be the correct ratio and was rewarded with my choice as I produced one of my most powerful road sprints to successfully outsprint Michael and WIN my very first Stage in the prestigious Rothmans Tour Of Southland. My determination to win can be clearly seen on my face here - another stunning capture by photographer and fellow Invercargill Cycling Club rider John McDonald: www.flickr.com/photos/35707376@N00/52067171403/in/album-7...
Epinephrine supplements, or more popularly known as adrenaline hormone, are supposed to raise the energy level of a person exercising in short intervals, making training sessions more effective. However, Epinephrine also robs muscle tissues of glycogen, turning it into free glucose, which lessens a person's recovery reserves, making it hard for people training to recover quickly.
A fungus (pl.: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the traditional eukaryotic kingdoms, along with Animalia, Plantae and either Protista or Protozoa and Chromista.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (i.e. they form a monophyletic group), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology (from the Greek μύκης mykes, mushroom). In the past mycology was regarded as a branch of botany, although it is now known that fungi are genetically more closely related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and also parasites. They may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment. They have long been used as a direct source of human food, in the form of mushrooms and truffles; as a leavening agent for bread; and in the fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological pesticides to control weeds, plant diseases, and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals, including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g., rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.
The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of the fungus kingdom, which has been estimated at 2.2 million to 3.8 million species. Of these, only about 148,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christiaan Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the first decade of the 21st century have helped reshape the classification within the fungi kingdom, which is divided into one subkingdom, seven phyla, and ten subphyla.
Etymology
The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos (σφόγγος 'sponge'), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm ('sponge') and Schimmel ('mold').
The word mycology is derived from the Greek mykes (μύκης 'mushroom') and logos (λόγος 'discourse'). It denotes the scientific study of fungi. The Latin adjectival form of "mycology" (mycologicæ) appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon. The word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. also refers to mycology as the study of fungi.
A group of all the fungi present in a particular region is known as mycobiota (plural noun, no singular). The term mycota is often used for this purpose, but many authors use it as a synonym of Fungi. The word funga has been proposed as a less ambiguous term morphologically similar to fauna and flora. The Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN) in August 2021 asked that the phrase fauna and flora be replaced by fauna, flora, and funga.
Characteristics
Fungal hyphae cells
Hyphal wall
Septum
Mitochondrion
Vacuole
Ergosterol crystal
Ribosome
Nucleus
Endoplasmic reticulum
Lipid body
Plasma membrane
Spitzenkörper
Golgi apparatus
Fungal cell cycle showing Dikaryons typical of Higher Fungi
Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Although inaccurate, the common misconception that fungi are plants persists among the general public due to their historical classification, as well as several similarities. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era). Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:
With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type. They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals).
With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.
With plants: Fungi have a cell wall and vacuoles. They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.
With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.
The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper. Both fungi and oomycetes grow as filamentous hyphal cells. In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells. There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.
In common with some plant and animal species, more than one hundred fungal species display bioluminescence.
Unique features:
Some species grow as unicellular yeasts that reproduce by budding or fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.
The fungal cell wall is made of a chitin-glucan complex; while glucans are also found in plants and chitin in the exoskeleton of arthropods, fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.
A whitish fan or funnel-shaped mushroom growing at the base of a tree.
Omphalotus nidiformis, a bioluminescent mushroom
Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs, which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks. Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure that fungi and animals do not have. Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants. Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.
Diversity
Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Some can survive the intense UV and cosmic radiation encountered during space travel. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans, parasites that have been responsible for a worldwide decline in amphibian populations. These organisms spend part of their life cycle as a motile zoospore, enabling them to propel itself through water and enter their amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.
As of 2020, around 148,000 species of fungi have been described by taxonomists, but the global biodiversity of the fungus kingdom is not fully understood. A 2017 estimate suggests there may be between 2.2 and 3.8 million species The number of new fungi species discovered yearly has increased from 1,000 to 1,500 per year about 10 years ago, to about 2000 with a peak of more than 2,500 species in 2016. In the year 2019, 1882 new species of fungi were described, and it was estimated that more than 90% of fungi remain unknown The following year, 2905 new species were described—the highest annual record of new fungus names. In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy. Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.
Mycology
Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.
The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus). Ancient peoples have used fungi as food sources—often unknowingly—for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.
History
Mycology became a systematic science after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera. Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated. Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christiaan Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. In the 20th and 21st centuries, advances in biochemistry, genetics, molecular biology, biotechnology, DNA sequencing and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.
Morphology
Microscopic structures
Monochrome micrograph showing Penicillium hyphae as long, transparent, tube-like structures a few micrometres across. Conidiophores branch out laterally from the hyphae, terminating in bundles of phialides on which spherical condidiophores are arranged like beads on a string. Septa are faintly visible as dark lines crossing the hyphae.
An environmental isolate of Penicillium
Hypha
Conidiophore
Phialide
Conidia
Septa
Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 µm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastomosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized. Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota. Coenocytic hyphae are in essence multinucleate supercells.
Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla,[63] and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.
Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella. Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.
Macroscopic structures
Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups. Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.
The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells. The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.
Growth and physiology
Time-lapse photography sequence of a peach becoming progressively discolored and disfigured
Mold growth covering a decaying peach. The frames were taken approximately 12 hours apart over a period of six days.
The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues.[71] The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi).[71] The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.
The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol. Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients. The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha. Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi, or growth by volume expansion during the development of mushroom stipes and other large organs. Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.
Fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known. This process might bear similarity to CO2 fixation via visible light, but instead uses ionizing radiation as a source of energy.
Reproduction
Two thickly stemmed brownish mushrooms with scales on the upper surface, growing out of a tree trunk
Polyporus squamosus
Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph (sexual reproduction) and the anamorph (asexual reproduction). Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.
Asexual reproduction
Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction. The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle. Deuteromycota (alternatively known as Deuteromycetes, conidial fungi, or mitosporic fungi) is not an accepted taxonomic clade and is now taken to mean simply fungi that lack a known sexual stage.
Sexual reproduction
See also: Mating in fungi and Sexual selection in fungi
Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies. Mating experiments between fungal isolates may identify species on the basis of biological species concepts. The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Fungi employ two mating systems: heterothallic species allow mating only between individuals of the opposite mating type, whereas homothallic species can mate, and sexually reproduce, with any other individual or itself.
Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).
In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook (crozier) at the hyphal septum. During cell division, the formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.
Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment. A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis. The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).
In fungi formerly classified as Zygomycota, haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.
Spore dispersal
The spores of most of the researched species of fungi are transported by wind. Such species often produce dry or hydrophobic spores that do not absorb water and are readily scattered by raindrops, for example. In other species, both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances.
Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection. For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g; the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below. Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The hydnoid fungi (tooth fungi) produce spores on pendant, tooth-like or spine-like projections. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies. Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.
Homothallism
In homothallic sexual reproduction, two haploid nuclei derived from the same individual fuse to form a zygote that can then undergo meiosis. Homothallic fungi include species with an Aspergillus-like asexual stage (anamorphs) occurring in numerous different genera, several species of the ascomycete genus Cochliobolus, and the ascomycete Pneumocystis jirovecii. The earliest mode of sexual reproduction among eukaryotes was likely homothallism, that is, self-fertile unisexual reproduction.
Other sexual processes
Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells. The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization and is likely required for hybridization between species, which has been associated with major events in fungal evolution.
Evolution
In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.
The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. The oldest fossilizied mycelium to be identified from its molecular composition is between 715 and 810 million years old. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.
In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).
Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.
Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess, the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary.
Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like "a massive compost heap".
Taxonomy
Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.
There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).
The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances.
The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. As of 2019, nine major lineages have been identified: Opisthosporidia, Chytridiomycota, Neocallimastigomycota, Blastocladiomycota, Zoopagomycotina, Mucoromycota, Glomeromycota, Ascomycota and Basidiomycota.
Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species). Previously considered to be "primitive" protozoa, they are now thought to be either a basal branch of the Fungi, or a sister group–each other's closest evolutionary relative.
The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.
The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.
The Neocallimastigomycota were earlier placed in the phylum Chytridiomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites). They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.
Microscopic view of a layer of translucent grayish cells, some containing small dark-color spheres
Arbuscular mycorrhiza seen under microscope. Flax root cortical cells containing paired arbuscules.
Cross-section of a cup-shaped structure showing locations of developing meiotic asci (upper edge of cup, left side, arrows pointing to two gray cells containing four and two small circles), sterile hyphae (upper edge of cup, right side, arrows pointing to white cells with a single small circle in them), and mature asci (upper edge of cup, pointing to two gray cells with eight small circles in them)
Diagram of an apothecium (the typical cup-like reproductive structure of Ascomycetes) showing sterile tissues as well as developing and mature asci.
Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually. The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago. Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota. Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina. Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.
The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).
Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans.
Fungus-like organisms
Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to an ambiregnal, duplicated taxonomy.
Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and take in nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.
The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.
The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi. Alternatively, Rozella can be classified as a basal fungal group.
The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom. Many Actinomycetales (Actinomycetota), a group with many filamentous bacteria, were also long believed to be fungi.
Ecology
Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.
Symbiosis
Many fungi have important symbiotic relationships with organisms from most if not all kingdoms. These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.
With plants
Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.
A microscopic view of blue-stained cells, some with dark wavy lines in them
The dark filaments are hyphae of the endophytic fungus Epichloë coenophiala in the intercellular spaces of tall fescue leaf sheath tissue
The mycorrhizal symbiosis is ancient, dating back to at least 400 million years. It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients. The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks". A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont. Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes. Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.
With algae and cyanobacteria
A green, leaf-like structure attached to a tree, with a pattern of ridges and depression on the bottom surface
The lichen Lobaria pulmonaria, a symbiosis of fungal, algal, and cyanobacterial species
Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes. Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession, and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions. They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves. As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 27% of known fungi—more than 19,400 species—are lichenized. Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.
With insects
Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Chaetothyriales for several purposes: as a food source, as a structural component of their nests, and as a part of an ant/plant symbiosis in the domatia (tiny chambers in plants that house arthropods). Ambrosia beetles cultivate various species of fungi in the bark of trees that they infest. Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae. At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests. Termites on the African savannah are also known to cultivate fungi, and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts. Fungi growing in dead wood are essential for xylophagous insects (e.g. woodboring beetles). They deliver nutrients needed by xylophages to nutritionally scarce dead wood. Thanks to this nutritional enrichment the larvae of the woodboring insect is able to grow and develop to adulthood. The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.
A thin brown stick positioned horizontally with roughly two dozen clustered orange-red leaves originating from a single point in the middle of the stick. These orange leaves are three to four times larger than the few other green leaves growing out of the stick, and are covered on the lower leaf surface with hundreds of tiny bumps. The background shows the green leaves and branches of neighboring shrubs.
The plant pathogen Puccinia magellanicum (calafate rust) causes the defect known as witch's broom, seen here on a barberry shrub in Chile.
Gram stain of Candida albicans from a vaginal swab from a woman with candidiasis, showing hyphae, and chlamydospores, which are 2–4 µm in diameter.
Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae, tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease, Cryphonectria parasitica responsible for chestnut blight, and Phymatotrichopsis omnivora causing Texas Root Rot, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets. Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed). This same principle is applied to fungi-feeding parasites, including Asterotremella albida, which feeds on the fruit bodies of other fungi both while they are living and after they are dead.
Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma, and Pneumocystis. Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.
As targets of mycoparasites
Organisms that parasitize fungi are known as mycoparasitic organisms. About 300 species of fungi and fungus-like organisms, belonging to 13 classes and 113 genera, are used as biocontrol agents against plant fungal diseases. Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms. Fungi can also become the target of infection by mycoviruses.
Communication
Main article: Mycorrhizal networks
There appears to be electrical communication between fungi in word-like components according to spiking characteristics.
Possible impact on climate
According to a study published in the academic journal Current Biology, fungi can soak from the atmosphere around 36% of global fossil fuel greenhouse gas emissions.
Mycotoxins
(6aR,9R)-N-((2R,5S,10aS,10bS)-5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-2H-oxazolo[3,2-a] pyrrolo[2,1-c]pyrazin-2-yl)-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg] quinoline-9-carboxamide
Ergotamine, a major mycotoxin produced by Claviceps species, which if ingested can cause gangrene, convulsions, and hallucinations
Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea. Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.
Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi. Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory). Many fungal secondary metabolites (or derivatives) are used medically, as described under Human use below.
Pathogenic mechanisms
Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen's virulence. Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis. The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.
Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages. Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response. Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.
Human use
See also: Human interactions with fungi
Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres
Saccharomyces cerevisiae cells shown with DIC microscopy
The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. Methods have been developed for genetic engineering of fungi, enabling metabolic engineering of fungal species. For example, genetic modification of yeast species—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms. Fungi-based industries are sometimes considered to be a major part of a growing bioeconomy, with applications under research and development including use for textiles, meat substitution and general fungal biotechnology.
Therapeutic uses
Modern chemotherapeutics
Many species produce metabolites that are major sources of pharmacologically active drugs.
Antibiotics
Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties. Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria. Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.
Other
Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections, and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom. Psilocybin from fungi is investigated for therapeutic use and appears to cause global increases in brain network integration. Fungi produce compounds that inhibit viruses and cancer cells. Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan. In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.
Traditional medicine
Upper surface view of a kidney-shaped fungus, brownish-red with a lighter yellow-brown margin, and a somewhat varnished or shiny appearance
Two dried yellow-orange caterpillars, one with a curly grayish fungus growing out of one of its ends. The grayish fungus is roughly equal to or slightly greater in length than the caterpillar, and tapers in thickness to a narrow end.
The fungi Ganoderma lucidum (left) and Ophiocordyceps sinensis (right) are used in traditional medicine practices
Certain mushrooms are used as supposed therapeutics in folk medicine practices, such as traditional Chinese medicine. Mushrooms with a history of such use include Agaricus subrufescens, Ganoderma lucidum, and Ophiocordyceps sinensis.
Cultured foods
Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings. Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation. Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso while Rhizopus species are used for making tempeh. Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli. Quorn, a meat substitute, is made from Fusarium venenatum.
"Wood Frogs are “cold blooded” (or more precisely, ectothermic), so their body temperature closely tracks the temperature around them. Temperatures have to dip slightly below 32 degrees Fahrenheit to freeze a frog, and ice begins to grow when an ice crystal touches the frog’s skin. Like falling dominoes, the ice triggers a cascade of particles that form as the temperature drops.
But these amphibians don’t just turn into a block of ice. A chain of events occurs to protect the freezing frog. Minutes after ice starts to form in the skin, a wood frog’s liver begins converting sugars, stored as glycogen, into glucose. This sugar is released from the liver and carried through the bloodstream to every tissue where it helps keep cells from completely dehydrating and shrinking.
As the wood frog is freezing, its heart continues pumping the protective glucose around its body, but the frog’s heart slows and eventually stops. All other organs stop functioning. The frog doesn’t use oxygen and actually appears to be dead. In fact, if you opened up a frozen frog, the organs would look like “beef jerky” and the frozen water around the organs like a “snow cone,” says Jon Costanzo, a physiological ecologist at Miami University in Ohio who studies freeze-tolerance.
When in its frogcicle state, as much as 70 percent of the water in a frog’s body can be frozen, write researchers Jack Layne and Richard Lee in their 1995 article (pdf) in Climate Research. Frogs can survive all winter like this, undergoing cycles of freezing and thawing." Scienceline.org
A camel (from Latin: camelus and Greek: κάμηλος (kamēlos) from Ancient Semitic: gāmāl) is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provide food (milk and meat) and textiles (fiber and felt from hair). Camels are working animals especially suited to their desert habitat and are a vital means of transport for passengers and cargo. There are three surviving species of camel. The one-humped dromedary makes up 94% of the world's camel population, and the two-humped Bactrian camel makes up 6%. The wild Bactrian camel is a separate species and is now critically endangered.
The word camel is also used informally in a wider sense, where the more correct term is "camelid", to include all seven species of the family Camelidae: the true camels (the above three species), along with the "New World" camelids: the llama, the alpaca, the guanaco, and the vicuña, which belong to the separate tribe Lamini. Camelids originated in North America during the Eocene, with the ancestor of modern camels, Paracamelus, migrating across the Bering land bridge into Asia during the late Miocene, around 6 million years ago.
Taxonomy
Extant species
Three species are extant:
ImageCommon nameScientific nameDistribution
Bactrian camelCamelus bactrianusDomesticated; Central Asia, including the historical region of Bactria.
Dromedary / Arabian camelCamelus dromedariusDomesticated; the Middle East, Sahara Desert, and South Asia; introduced to Australia
Wild Bactrian camelCamelus ferusRemote areas of northwest China and Mongolia
Biology
The average life expectancy of a camel is 40 to 50 years. A full-grown adult dromedary camel stands 1.85 m (6 ft 1 in) at the shoulder and 2.15 m (7 ft 1 in) at the hump. Bactrian camels can be a foot taller. Camels can run at up to 65 km/h (40 mph) in short bursts and sustain speeds of up to 40 km/h (25 mph). Bactrian camels weigh 300 to 1,000 kg (660 to 2,200 lb) and dromedaries 300 to 600 kg (660 to 1,320 lb). The widening toes on a camel's hoof provide supplemental grip for varying soil sediments.
The male dromedary camel has an organ called a dulla in his throat, a large, inflatable sac that he extrudes from his mouth when in rut to assert dominance and attract females. It resembles a long, swollen, pink tongue hanging out of the side of the camel's mouth. Camels mate by having both male and female sitting on the ground, with the male mounting from behind. The male usually ejaculates three or four times within a single mating session. Camelids are the only ungulates to mate in a sitting position.
Ecological and behavioral adaptations
Camel humps store fat, which are used as nourishment when food is scarce. If a camel uses the fat inside the hump, the hump will become limp and droop down
Camels do not directly store water in their humps; they are reservoirs of fatty tissue. When this tissue is metabolized, it yields a greater mass of water than that of the fat processed. This fat metabolization, while releasing energy, causes water to evaporate from the lungs during respiration (as oxygen is required for the metabolic process): overall, there is a net decrease in water.
Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water. The dromedary camel can drink as seldom as once every 10 days even under very hot conditions, and can lose up to 30% of its body mass due to dehydration. Unlike other mammals, camels' red blood cells are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: a 600 kg (1,300 lb) camel can drink 200 L (53 US gal) of water in three minutes.
Camels are able to withstand changes in body temperature and water consumption that would kill most other mammals. Their temperature ranges from 34 °C (93 °F) at dawn and steadily increases to 40 °C (104 °F) by sunset, before they cool off at night again. In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day. Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a rete mirabile, a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain. Camels rarely sweat, even when ambient temperatures reach 49 °C (120 °F). Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight in water, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance.
When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water. Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.
Domesticated camel calves lying in sternal recumbency, a position that aids heat loss
The camel's thick coat insulates it from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating. During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn. The camel's long legs help by keeping its body farther from the ground, which can heat up to 70 °C (158 °F). Dromedaries have a pad of thick tissue over the sternum called the pedestal. When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body.
Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their translucent third eyelid (also known as the nictitating membrane). The camels' gait and widened feet help them move without sinking into the sand.
The kidneys and intestines of a camel are very efficient at reabsorbing water. Camels' kidneys have a 1:4 cortex to medulla ratio. Thus, the medullary part of a camel's kidney occupies twice as much area as a cow's kidney. Secondly, renal corpuscles have a smaller diameter, which reduces surface area for filtration. These two major anatomical characteristics enable camels to conserve water and limit the volume of urine in extreme desert conditions. Camel urine comes out as a thick syrup, and camel faeces are so dry that they do not require drying when used to fuel fires.
The camel immune system differs from those of other mammals. Normally, the Y-shaped antibody molecules consist of two heavy (or long) chains along the length of the Y, and two light (or short) chains at each tip of the Y. Camels, in addition to these, also have antibodies made of only two heavy chains, a trait that makes them smaller and more durable. These "heavy-chain-only" antibodies, discovered in 1993, are thought to have developed 50 million years ago, after camelids split from ruminants and pigs. Camels suffer from surra caused by Trypanosoma evansi wherever camels are domesticated in the world: 2 and resultantly camels have evolved trypanolytic antibodies as with many mammals. In the future, nanobody/single-domain antibody therapy will surpass natural camel antibodies by reaching locations currently unreachable due to natural antibodies' larger size.: 788 Such therapies may also be suitable for other mammals.: 788 Tran et al. 2009 provides a new reference test for surra (T. evansi) of camel. They use recombinant Invariant Surface Glycoprotein 75 (rISG75, an Invariant Surface Glycoprotein) and ELISA. The Tran test has high test specificity and appears likely to work just as well for T. evansi in other hosts, and for a pan-Trypanozoon test, which would also be useful for T. b. brucei, T. b. gambiense, T. b. rhodesiense, and T. equiperdum.
Genetics
The karyotypes of different camelid species have been studied earlier by many groups, but no agreement on chromosome nomenclature of camelids has been reached. A 2007 study flow sorted camel chromosomes, building on the fact that camels have 37 pairs of chromosomes (2n=74), and found that the karyotype consisted of one metacentric, three submetacentric, and 32 acrocentric autosomes. The Y is a small metacentric chromosome, while the X is a large metacentric chromosome.
The hybrid camel, a hybrid between Bactrian and dromedary camels, has one hump, though it has an indentation 4–12 cm (1.6–4.7 in) deep that divides the front from the back. The hybrid is 2.15 m (7 ft 1 in) at the shoulder and 2.32 m (7 ft 7 in) tall at the hump. It weighs an average of 650 kg (1,430 lb) and can carry around 400 to 450 kg (880 to 990 lb), which is more than either the dromedary or Bactrian can.
According to molecular data, the wild Bactrian camel (C. ferus) separated from the domestic Bactrian camel (C. bactrianus) about 1 million years ago. New World and Old World camelids diverged about 11 million years ago. In spite of this, these species can hybridize and produce viable offspring. The cama is a camel-llama hybrid bred by scientists to see how closely related the parent species are. Scientists collected semen from a camel via an artificial vagina and inseminated a llama after stimulating ovulation with gonadotrophin injections. The cama is halfway in size between a camel and a llama and lacks a hump. It has ears intermediate between those of camels and llamas, longer legs than the llama, and partially cloven hooves. Like the mule, camas are sterile, despite both parents having the same number of chromosomes.
Evolution
The earliest known camel, called Protylopus, lived in North America 40 to 50 million years ago (during the Eocene). It was about the size of a rabbit and lived in the open woodlands of what is now South Dakota. By 35 million years ago, the Poebrotherium was the size of a goat and had many more traits similar to camels and llamas. The hoofed Stenomylus, which walked on the tips of its toes, also existed around this time, and the long-necked Aepycamelus evolved in the Miocene. The split between the tribes Camelini, which contains modern camels and Lamini, modern llamas, alpacas, vicuñas, and guanacos, is estimated to have occurred over 16 million years ago.
The ancestor of modern camels, Paracamelus, migrated into Eurasia from North America via Beringia during the late Miocene, between 7.5 and 6.5 million years ago. During the Pleistocene, around 3 to 1 million years ago, the North American Camelidae spread to South America as part of the Great American Interchange via the newly formed Isthmus of Panama, where they gave rise to guanacos and related animals. Populations of Paracamelus continued to exist in the North American Arctic into the Early Pleistocene. This creature is estimated to have stood around nine feet (2.7 metres) tall. The Bactrian camel diverged from the dromedary about 1 million years ago, according to the fossil record.
The last camel native to North America was Camelops hesternus, which vanished along with horses, short-faced bears, mammoths and mastodons, ground sloths, sabertooth cats, and many other megafauna as part of the Quaternary extinction event, coinciding with the migration of humans from Asia at the end of the Pleistocene, around 13–11,000 years ago.
Domestication
Like horses, camels originated in North America and eventually spread across Beringia to Asia. They survived in the Old World, and eventually humans domesticated them and spread them globally. Along with many other megafauna in North America, the original wild camels were wiped out during the spread of the first indigenous peoples of the Americas from Asia into North America, 10 to 12,000 years ago; although fossils have never been associated with definitive evidence of hunting.
Most camels surviving today are domesticated. Although feral populations exist in Australia, India and Kazakhstan, wild camels survive only in the wild Bactrian camel population of the Gobi Desert.
History
When humans first domesticated camels is disputed. Dromedaries may have first been domesticated by humans in Somalia or South Arabia sometime during the 3rd millennium BC, the Bactrian in central Asia around 2,500 BC, as at Shar-i Sokhta (also known as the Burnt City), Iran. A study from 2016, which genotyped and used world-wide sequencing of modern and ancient mitochondrial DNA (mtDNA), suggested that they were initially domesticated in the southeast Arabian Peninsula, with the Bactrian type later being domesticated around Central Asia.
Martin Heide's 2010 work on the domestication of the camel tentatively concludes that humans had domesticated the Bactrian camel by at least the middle of the third millennium somewhere east of the Zagros Mountains, with the practice then moving into Mesopotamia. Heide suggests that mentions of camels "in the patriarchal narratives may refer, at least in some places, to the Bactrian camel", while noting that the camel is not mentioned in relationship to Canaan. Heide and Joris Peters reasserted that conclusion in their 2021 study on the subject.
In 2009-2013, excavations in the Timna Valley by Lidar Sapir-Hen and Erez Ben-Yosef discovered what may be the earliest domestic camel bones yet found in Israel or even outside the Arabian Peninsula, dating to around 930 BC. This garnered considerable media coverage, as it is strong evidence that the stories of Abraham, Jacob, Esau, and Joseph were written after this time.
The existence of camels in Mesopotamia—but not in the eastern Mediterranean lands—is not a new idea. The historian Richard Bulliet did not think that the occasional mention of camels in the Bible meant that the domestic camels were common in the Holy Land at that time. The archaeologist William F. Albright, writing even earlier, saw camels in the Bible as an anachronism.
The official report by Sapir-Hen and Ben-Joseph notes:
The introduction of the dromedary camel (Camelus dromedarius) as a pack animal to the southern Levant ... substantially facilitated trade across the vast deserts of Arabia, promoting both economic and social change (e.g., Kohler 1984; Borowski 1998: 112–116; Jasmin 2005). This ... has generated extensive discussion regarding the date of the earliest domestic camel in the southern Levant (and beyond) (e.g., Albright 1949: 207; Epstein 1971: 558–584; Bulliet 1975; Zarins 1989; Köhler-Rollefson 1993; Uerpmann and Uerpmann 2002; Jasmin 2005; 2006; Heide 2010; Rosen and Saidel 2010; Grigson 2012). Most scholars today agree that the dromedary was exploited as a pack animal sometime in the early Iron Age (not before the 12th century [BC])
and concludes:
Current data from copper smelting sites of the Aravah Valley enable us to pinpoint the introduction of domestic camels to the southern Levant more precisely based on stratigraphic contexts associated with an extensive suite of radiocarbon dates. The data indicate that this event occurred not earlier than the last third of the 10th century [BC] and most probably during this time. The coincidence of this event with a major reorganization of the copper industry of the region—attributed to the results of the campaign of Pharaoh Shoshenq I—raises the possibility that the two were connected, and that camels were introduced as part of the efforts to improve efficiency by facilitating trade.
Textiles
Main article: Camel hair
Desert tribes and Mongolian nomads use camel hair for tents, yurts, clothing, bedding and accessories. Camels have outer guard hairs and soft inner down, and the fibers are sorted by color and age of the animal. The guard hairs can be felted for use as waterproof coats for the herdsmen, while the softer hair is used for premium goods. The fiber can be spun for use in weaving or made into yarns for hand knitting or crochet. Pure camel hair is recorded as being used for western garments from the 17th century onwards, and from the 19th century a mixture of wool and camel hair was used.
Military uses
Main article: Camel cavalry
By at least 1200 BC the first camel saddles had appeared, and Bactrian camels could be ridden. The first saddle was positioned to the back of the camel, and control of the Bactrian camel was exercised by means of a stick. However, between 500 and 100 BC, Bactrian camels came into military use. New saddles, which were inflexible and bent, were put over the humps and divided the rider's weight over the animal. In the seventh century BC the military Arabian saddle evolved, which again improved the saddle design slightly.
Military forces have used camel cavalries in wars throughout Africa, the Middle East, and into the modern-day Border Security Force (BSF) of India (though as of July 2012, the BSF planned the replacement of camels with ATVs). The first documented use of camel cavalries occurred in the Battle of Qarqar in 853 BC. Armies have also used camels as freight animals instead of horses and mules.
The East Roman Empire used auxiliary forces known as dromedarii, whom the Romans recruited in desert provinces. The camels were used mostly in combat because of their ability to scare off horses at close range (horses are afraid of the camels' scent), a quality famously employed by the Achaemenid Persians when fighting Lydia in the Battle of Thymbra (547 BC).
19th and 20th centuries
A photo of Bulgarian military-transport camels in 1912
A camel caravan of the Bulgarian military during the First Balkan War, 1912
The United States Army established the U.S. Camel Corps, stationed in California, in the 19th century.[19] One may still see stables at the Benicia Arsenal in Benicia, California, where they nowadays serve as the Benicia Historical Museum. Though the experimental use of camels was seen as a success (John B. Floyd, Secretary of War in 1858, recommended that funds be allocated towards obtaining a thousand more camels), the outbreak of the American Civil War in 1861 saw the end of the Camel Corps: Texas became part of the Confederacy, and most of the camels were left to wander away into the desert.
France created a méhariste camel corps in 1912 as part of the Armée d'Afrique in the Sahara in order to exercise greater control over the camel-riding Tuareg and Arab insurgents, as previous efforts to defeat them on foot had failed. The Free French Camel Corps fought during World War II, and camel-mounted units remained in service until the end of French rule over Algeria in 1962.
In 1916, the British created the Imperial Camel Corps. It was originally used to fight the Senussi, but was later used in the Sinai and Palestine Campaign in World War I. The Imperial Camel Corps comprised infantrymen mounted on camels for movement across desert, though they dismounted at battle sites and fought on foot. After July 1918, the Corps began to become run down, receiving no new reinforcements, and was formally disbanded in 1919.
In World War I, the British Army also created the Egyptian Camel Transport Corps, which consisted of a group of Egyptian camel drivers and their camels. The Corps supported British war operations in Sinai, Palestine, and Syria by transporting supplies to the troops.
The Somaliland Camel Corps was created by colonial authorities in British Somaliland in 1912; it was disbanded in 1944.
Bactrian camels were used by Romanian forces during World War II in the Caucasian region. At the same period the Soviet units operating around Astrakhan in 1942 adopted local camels as draft animals due to shortage of trucks and horses, and kept them even after moving out of the area. Despite severe losses, some of these camels ended up as far west as to Berlin itself.
The Bikaner Camel Corps of British India fought alongside the British Indian Army in World Wars I and II.
The Tropas Nómadas (Nomad Troops) were an auxiliary regiment of Sahrawi tribesmen serving in the colonial army in Spanish Sahara (today Western Sahara). Operational from the 1930s until the end of the Spanish presence in the territory in 1975, the Tropas Nómadas were equipped with small arms and led by Spanish officers. The unit guarded outposts and sometimes conducted patrols on camelback.
21st century competition
At the King Abdulaziz Camel Festival, in Saudi Arabia, thousands of camels are paraded and are judged on their lips and humps. The festival also features camel racing and camel milk tasting and has combined prize money of $57m (£40m). In 2018, 12 camels were disqualified from the beauty contest after it was discovered their owners had tried to improve their camel's good looks with injections of botox, into the animals' lips, noses and jaws. In 2021 over 40 camels were disqualified for acts of tampering and deception in beautifying camels.
Food uses
Dairy
Main article: Camel milk
Camel milk is a staple food of desert nomad tribes and is sometimes considered a meal itself; a nomad can live on only camel milk for almost a month.
Camel milk can readily be made into yogurt, but can only be made into butter if it is soured first, churned, and a clarifying agent is then added. Until recently, camel milk could not be made into camel cheese because rennet was unable to coagulate the milk proteins to allow the collection of curds. Developing less wasteful uses of the milk, the FAO commissioned Professor J.P. Ramet of the École Nationale Supérieure d'Agronomie et des Industries Alimentaires, who was able to produce curdling by the addition of calcium phosphate and vegetable rennet in the 1990s. The cheese produced from this process has low levels of cholesterol and is easy to digest, even for the lactose intolerant.
Camels provide food in the form of meat and milk. Approximately 3.3 million camels and camelids are slaughtered each year for meat worldwide. A camel carcass can provide a substantial amount of meat. The male dromedary carcass can weigh 300–400 kg (661–882 lb), while the carcass of a male Bactrian can weigh up to 650 kg (1,433 lb). The carcass of a female dromedary weighs less than the male, ranging between 250 and 350 kg (550 and 770 lb). The brisket, ribs and loin are among the preferred parts, and the hump is considered a delicacy. The hump contains "white and sickly fat", which can be used to make the khli (preserved meat) of mutton, beef, or camel. On the other hand, camel milk and meat are rich in protein, vitamins, glycogen, and other nutrients making them essential in the diet of many people. From chemical composition to meat quality, the dromedary camel is the preferred breed for meat production. It does well even in arid areas due to its unusual physiological behaviors and characteristics, which include tolerance to extreme temperatures, radiation from the sun, water paucity, rugged landscape and low vegetation. Camel meat is reported to taste like coarse beef, but older camels can prove to be very tough, although camel meat becomes tenderer the more it is cooked.
Camel is one of the animals that can be ritually slaughtered and divided into three portions (one for the home, one for extended family/social networks, and one for those who cannot afford to slaughter an animal themselves) for the qurban of Eid al-Adha.
The Abu Dhabi Officers' Club serves a camel burger mixed with beef or lamb fat in order to improve the texture and taste. In Karachi, Pakistan, some restaurants prepare nihari from camel meat. Specialist camel butchers provide expert cuts, with the hump considered the most popular.
Camel meat has been eaten for centuries. It has been recorded by ancient Greek writers as an available dish at banquets in ancient Persia, usually roasted whole. The Roman emperor Heliogabalus enjoyed camel's heel. Camel meat is mainly eaten in certain regions, including Eritrea, Somalia, Djibouti, Saudi Arabia, Egypt, Syria, Libya, Sudan, Ethiopia, Kazakhstan, and other arid regions where alternative forms of protein may be limited or where camel meat has had a long cultural history. Camel blood is also consumable, as is the case among pastoralists in northern Kenya, where camel blood is drunk with milk and acts as a key source of iron, vitamin D, salts and minerals.
A 2005 report issued jointly by the Saudi Ministry of Health and the United States Centers for Disease Control and Prevention details four cases of human bubonic plague resulting from the ingestion of raw camel liver.
Australia
Camel meat is also occasionally found in Australian cuisine: for example, a camel lasagna is available in Alice Springs. Australia has exported camel meat, primarily to the Middle East but also to Europe and the US, for many years. The meat is very popular among East African Australians, such as Somalis, and other Australians have also been buying it. The feral nature of the animals means they produce a different type of meat to farmed camels in other parts of the world, and it is sought after because it is disease-free, and a unique genetic group. Demand is outstripping supply, and governments are being urged not to cull the camels, but redirect the cost of the cull into developing the market. Australia has seven camel dairies, which produce milk, cheese and skincare products in addition to meat.
Religion
Islam
Main article: Animals in Islam
Muslims consider camel meat halal (Arabic: حلال, 'allowed'). However, according to some Islamic schools of thought, a state of impurity is brought on by the consumption of it. Consequently, these schools hold that Muslims must perform wudhu (ablution) before the next time they pray after eating camel meat. Also, some Islamic schools of thought consider it haram (Arabic: حرام, 'forbidden') for a Muslim to perform Salat in places where camels lie, as it is said to be a dwelling place of the Shaytan (Arabic: شيطان, 'Devil'). According to Abu Yusuf (d.798), the urine of camel may be used for medical treatment if necessary, but according to Abū Ḥanīfah, the drinking of camel urine is discouraged.
The Islamic texts contain several stories featuring camels. In the story of the people of Thamud, the prophet Salih miraculously brings forth a naqat (Arabic: ناقة, 'milch-camel') out of a rock. After the prophet Muhammad migrated from Mecca to Medina, he allowed his she-camel to roam there; the location where the camel stopped to rest determined the location where he would build his house in Medina.
Judaism
See also: Food and drink prohibitions
According to Jewish tradition, camel meat and milk are not kosher. Camels possess only one of the two kosher criteria; although they chew their cud, they do not possess cloven hooves: "But these you shall not eat among those that bring up the cud and those that have a cloven hoof: the camel, because it brings up its cud, but does not have a [completely] cloven hoof; it is unclean for you."
Cultural depictions
What may be the oldest carvings of camels were discovered in 2018 in Saudi Arabia. They were analysed by researchers from several scientific disciplines and, in 2021, were estimated to be 7,000 to 8,000 years old. The dating of rock art is made difficult by the lack of organic material in the carvings that may be tested, so the researchers attempting to date them tested animal bones found associated with the carvings, assessed erosion patterns, and analysed tool marks in order to determine a correct date for the creation of the sculptures. This Neolithic dating would make the carvings significantly older than Stonehenge (5,000 years old) and the Egyptian pyramids at Giza (4,500 years old) and it predates estimates for the domestication of camels.
Distribution and numbers
A view into a canyon: many camels gathering around a watering hole
Camels in the Guelta d'Archei, in northeastern Chad
There are approximately 14 million camels alive as of 2010, with 90% being dromedaries. Dromedaries alive today are domesticated animals (mostly living in the Horn of Africa, the Sahel, Maghreb, Middle East and South Asia). The Horn region alone has the largest concentration of camels in the world, where the dromedaries constitute an important part of local nomadic life. They provide nomadic people in Somalia and Ethiopia with milk, food, and transportation.
Over one million dromedary camels are estimated to be feral in Australia, descended from those introduced as a method of transport in the 19th and early 20th centuries. This population is growing about 8% per year; it was estimated at around 700,000 in 2008. Representatives of the Australian government have culled more than 100,000 of the animals in part because the camels use too much of the limited resources needed by sheep farmers.
A small population of introduced camels, dromedaries and Bactrians, wandered through Southwestern United States after having been imported in the 19th century as part of the U.S. Camel Corps experiment. When the project ended, they were used as draft animals in mines and escaped or were released. Twenty-five U.S. camels were bought and exported to Canada during the Cariboo Gold Rush.
The Bactrian camel is, as of 2010, reduced to an estimated 1.4 million animals, most of which are domesticated. The Wild Bactrian camel is a separate species and is the only truly wild (as opposed to feral) camel in the world. The wild camels are critically endangered and number approximately 1400, inhabiting the Gobi and Taklamakan Deserts in China and Mongolia.
The Jardin des plantes (French for "Garden of the Plants"), also known as the Jardin des plantes de Paris (French: [ʒaʁdɛ̃ dɛ plɑ̃t də paʁi]) when distinguished from other jardins des plantes in other cities, is the main botanical garden in France. The term Jardin des plantes is the official name in the present day, but it is in fact an elliptical form of Jardin royal des plantes médicinales ("Royal Garden of the Medicinal Plants"), which is related to the original purpose of the garden back in the 17th century.
Headquarters of the Muséum national d'histoire naturelle (National Museum of Natural History), the Jardin des plantes is situated in the 5th arrondissement, Paris, on the left bank of the river Seine, and covers 28 hectares (280,000 m2). Since 24 March 1993,[2] the entire garden and its contained buildings, archives, libraries, greenhouses, ménagerie (a zoo), works of art, and specimens' collection are classified as a national historical landmark in France (labelled monument historique).
Garden plan
The grounds of the Jardin des plantes include four buildings containing exhibited specimens. These buildings are officially considered as museums following the French law (they are labelled musée de France) and the French Museum of Natural History calls them galeries (French for 'galleries'):
The grande galerie de l'Évolution ('Gallery of Evolution') was inaugurated in 1889 as the galerie de Zoologie ('Gallery of Zoology'). In 1994, the gallery was renamed with its current name, grande galerie de l'Évolution, and its exhibited specimens were completely reorganised so that the visitor is oriented by the common thread of the evolution as the major subject treated by the gallery.
The galerie de Minéralogie et de Géologie ('Gallery of Mineralogy and Geology'), a mineralogy museum, built as of 1833, inaugurated in 1837.
The galerie de Paléontologie et d'Anatomie comparée ('Gallery of Paleontology and Comparative Anatomy'), a comparative anatomy museum in the ground floor and a paleontology museum in the first and second floors. The building was inaugurated in 1898.
The galerie de Botanique ('Gallery of Botany'), inaugurated in 1935 thanks to funds provided by the Rockefeller Foundation, contains botany laboratories and the French Muséum's National Herbarium (the biggest in the world with a collection of almost 8 million samples of plants). The building also contains a small permanent exhibition about botany.[citation needed]
In addition to the gardens and the galleries, there is also a small zoo, the ménagerie du Jardin des plantes, founded in 1795 by Bernardin de Saint-Pierre from animals of the ménagerie royale de Versailles, the menagerie at Versailles, which was dismantled during the French Revolution.[citation needed]
The Jardin des plantes maintains a botanical school, which trains botanists, constructs demonstration gardens, and exchanges seeds to maintain biotic diversity. About 4,500 plants are arranged by family on a one hectare (10,000 m2) plot. Three hectares are devoted to horticultural displays of decorative plants. An Alpine garden has 3,000 species with world-wide representation. Specialized buildings, such as a large Art Deco winter garden, and Mexican and Australian hothouses display regional plants, not native to France. The Rose Garden, created in 1990, has hundreds of species of roses and rose trees
The garden was formally founded in 1635 as the Royal Garden of Medicinal Plants by an edict of King Louis XIII. The garden was put under the authority of the Physician of the king, Guy de la Brosse. It was staffed by a group of "demonstrateurs", who lectured visitors, particularly future physicians and pharmacists, on botany, chemistry, and geology, illustrated by the garden collections.[3]
In 1673, under Louis XIV, and his new royal physician and director of the Garden, Guy-Crescent Fagon, great-nephew of Guy de la Brosse, the garden was given a new amphitheater, where dissections and other medical courses were conducted. The lecturers included the celebrated physician and anatomist Claude Perrault, who was equally famous as the architect; he designed the facade of the Louvre Palace.
In the early 18th century, the chateau was given an additional floor to house the collections the royal botanist's medicinal plant collection. This section was gradually turned into galleries to display the royal collection of minerals. At the same time, the greenhouses on the west and south were enlarged, to hold the plants brought back to France by numerous scientific expeditions around the world. New plants were studied, dried, and cataloged. A group of artists made Herbiers, books with detailed illustrations of each new plant, and the plants of the collection were carefully studied for their possible medical or culinary uses.[4] One example was the group of coffee plants brought from Java to Paris, which were raised and studied by Antoine de Jussieu for their possible medical and commercial use. His studies led to the plantation of coffee in the French colonies of North America.
The most celebrated head of the garden was Georges-Louis Leclerc, who served as its head from 1739 until his death in 1788. While director of the garden, he also owned and operated a large and successful iron works and foundry in Burgundy, but lived in the garden, in the house that now carries his name. Buffon was responsible for doubling the size of the garden, expanding down to the banks of Seine. He enlarged the Cabinet of Natural History in the main building, and added a new gallery to the south. He also brought into the scientific community of the garden a team of important botanists and naturalists, including Jean Baptiste Lamarck, author of one of the earliest theories of Evolution,[6]
Under the sponsorship of Buffon, explorers and botanists were sent to different corners of the world to collect specimens for garden and museum. Michel Adanson was sent to Senegal, and the navigator La Perouse to the islands of the Pacific. They returned with shiploads of specimens, which were carefully studied and classified. This research caused a conflict between the scientists of Royal Gardens and the professors of the Sorbonne over the question of Evolution. The scientists, led by Buffon and his followers, claimed that natural species gradually evolved, while the theologians of the Sorbonne insisted that nature was exactly as it was at the time of the Creation. Since the scientists had the backing of the Royal court, they were able to continue their studies and publish their work
On June 7, 1793, in the course of the French Revolution, the new government, the National Convention, ordered a complete transformation of the former royal institutions. They created a new Museum of Arts and Techniques, transformed the Louvre from a royal residence to a museum of art, and joined the Royal Garden of Plants and the Cabinet of Natural Sciences together into a single organization: the Museum of Natural History. It also received a number of important collections which had belonged to members of the aristocracy, such as a famous group of wax models illustrating anatomy which had been created by André Pinson.[8]
The Museum and gardens also benefited from the 1798 expedition launched by First Consul Napoleon Bonaparte to Egypt; the military force was accompanied by one hundred and fifty-four botanists, astronomers, archeologists, chemists, artists and other scholars, including Gaspard Monge, Joseph Fourier, and Claude Louis Berthollet. Drawings and paintings of their findings are found in the collections of the Natural History Museum.[8]
The holdings today include 6,963 specimens of the herbarium collection of Joseph Tournefort, donated on his death to the Jardin du Roi.[9]
The major addition to the garden in the late 18th century was the Ménagerie du Jardin des plantes. It was proposed in 1792 by Bernardin de Saint-Pierre, the intendant of the gardens, in large part to rescue the animals of the royal menagerie at the Palace of Versailles, who had been largely abandoned during the Revolution. The Duke of Orleans had a similar private zoo, also abandoned. At the same time the government of the Convention ordered the seizure of all the animals put on public display by various circuses in Paris. In 1795, the government acquired the Hôtel de Magné, the large estate of a French nobleman next to the gardens, and installed the large cages that had housed the animals at Versailles. It went through a very difficult early period, when the majority of the animals died, before it was given sufficient funding and more suitable structures by Napoleon. It became the home of animals brought back to France in scientific expeditions in the early 19th century, including a famous giraffe given to King Charles X by the Sultan of Cairo in 1827.[10]
On 25 August 1944, Allied American troops (2nd DB) were stationed here for the night after the Liberation of Paris from Nazi Germany.[11]
Late 19th–20th century – additions and experiments
Throughout the 19th and early 20th century, the primary mission of the gardens and museums was research. Working in the laboratories there, the chemist Eugene Chevreul first isolated fatty acids and cholesterol, and studied the chemistry of vegetal dyes. The physiologist Claude Bernard studied the functions of the glycogen in the liver. In 1896, the physicist Henri Becquerel, working in a laboratory in the museum, discovered radioactivity. He wrapped uranium salts together with an unexposed photographic plate wrapped in black cloth, to keep out the sunlight. When he unwrapped them, the photographic plate had changed color from exposure to the radiation. He received the Nobel Prize in 1903 for his discovery.[12]
The Gallery of Paleontology and of Comparative Anatomy was opened in 1898, replacing structures built between 1795 and 1807, to contain and display the thousands of skeletons the museum had collected. The buildings of menagerie were also expanded, with the construction of immense Bird House, by architect Jules André, 12 meters high, 37 meters long and 25 meters long,[13]
The appearance of the gardens changed in late 19th and early 20th century with the construction of new buildings. In 1877, the gallery of zoology, the landmark building that overlooks the formal garden, designed by Jules André, was begun. It was built to contain the immense zoological collections of the museum; the central hall is a landmark of iron construction, comparable to the Grand Palais and the Musée d'Orsay. It was inaugurated in 1888, but thereafter suffered from a long lack of maintenance. It was closed in 1965, In the 1980s, a new home was found for the museum's gigantic collections. The Zoothêque, was constructed between 1980 and 1986 underneath the Esplanade Milne-Edwards, directly in front of the Gallery of Zoology. It is accessible only to researchers, and contains the thirty million specimens of insects, five hundred thousand fish and reptiles, one hundred fifty thousand birds, and seven thousand other animals. The building above underwent a major renovation from 1991 to 1994, to house the updated Grand Gallery of Evolution.[12]
National Museum of Natural History
Main article: National Museum of Natural History, France
The National Museum of Natural History has been called "the Louvre of the Natural Sciences." It is contained in a five buildings laid out along the formal garden; the Gallery of Evolution; the Gallery of Mineralogy and Geology; the Gallery of Botany; the Gallery of Paleontology and Comparative Anatomy; and the Laboratory of Entomology
The Grand Gallery of Evolution was designed by Jules André, whose other works in Paris included, in collaboration with Henri Labrouste. the Beaux-arts Bibliotheque National. He became architect of the museum in 1867, and his works are found throughout the Jardin des Plantes. It opened during the Paris Universal Exposition of 1889, though it was not finished as intended; it still lacks a grand facade on the side of rue Geoffroy-Saint-Hilaire. The main facade, facing the two principal alleys of the formal garden, is flanked by two lantern towers. A series of medallions between the bays on the main facade overlooking the garden honors ten of the notable scientists who have worked in the Museum along with an allegorical statue of a woman holding an open book of knowledge.[15]
While the exterior is Beaux-Arts architecture, the interior iron structure was entirely modern, contemporary with the Grand Palais and the new railroad station of the gare d'Orsay (now the Musée d'Orsay). It encloses a rectangular hall 55 meters long, 25 meters wide and 15 meters high, with the glass roof of one thousand square meters supported by rows of slender iron columns. The structure deteriorated, had to be closed in 1965, then underwent extensive restoration between 1991 and 1995. It now presents, through preserved animals and media displays, the evolution of species. It gives special attention to species that has disappeared or are endangered. The collection of preserved animals includes the rhinoceros brought to France in the 18th century by Louis XV.
In front of the Gallery of Mineralogy and Geology stands one of the trees of the royal garden, a Sophora Japonica tree planted by Bernard de Jussieu in 1747. The gallery was constructed between 1833 and 1837 by Charles Rohault de Fleury in neoclassical style, with triangular frontons and pillars. The collection inside includes some six hundred thousand stones, gens, and fossils. Among the notable exhibits is the petrified trunk of bald cypress tree from the tertiary geological era, discovered in Essonne region of France in 1986.
In front of the Gallery of Botany is the oldest tree in Paris, a "Robinier Faux Acacia" brought to France from America in 1601. The gallery was built in 1930–35 with a grant from the Rockefeller Foundation. The gallery keeps the Herbier National, specimens of all known plant species, with 7.5 million plants represented. The ground floor gallery is used for temporary exhibitions.
This gallery is sited next to the Iris garden, which contains 260 varieties of Iris. The building was constructed between 1894 and 1897 by Ferdinand Dutert, a specialist in metallic architecture, whose most famous building was the Gallery of Machines at the 1889 Paris Exposition. The gallery was expanded in 1961 with a brick addition by architect Henri Delage. The interior is highly decorated with lace-like iron stairways and detail. It displays a large collection of fossilized skeletons of dinosaurs and other large vertebrates.
The garden covers an area of twenty-four hectares (59.3 acres). It is bordered by the River Seine on the east, on the west by the Rue Geofroy-Saint-Hilaire, on the south by the Rue Buffon, and on the north by Rue Cuvier, all streets named for French scientists whose studies were carried out within the garden and its museums.
The main entrance is on the east, along the Seine, at Place Valhubert, reaching to the Grand Gallery, which copies its width. It is in the style of a French formal garden and extends for five hundred meters (547 yards) between two geometrically-trimmed rows of platane trees. Its rectangula beds contain over a thousand plants. This part of the garden is bordered on the left by a row of galleries, and on the right by the School of Botany, the Alpine Garden, and greenhouses.[19]
The iron grill gateways and fence at Place Valubuert were created in the beginning of the formal garden on the east is a statue of the botanist Jean-Baptiste Lamarck, the director the school of botany beginning in 1788. He is best known for devising the first coherent theory of biological evolution.[20]
At the other end of the formal garden, facing the Grand gallery, is a statue of another major figure in the garden's history, the naturalist Buffon, in a dressing gown, seated comfortably in an armchair atop the skin of a lion, holding a bird in his hand. Between the statue and the Gallery is the Esplanade Mine Edwards, beneath which is the Zoothéque, the massive underground storage area for the museum's collections. It is not open to the public.
Four large serres chaudes, or greenhouses, are placed in a row to the right front of the Gallery of Evolution. facing onto the Esplanade Milne-Edwards. They replaced the earliest greenhouses, built on the same site in the early 18th century, to house the plants brought to France from tropical climates by French explorers and naturalists. The Mexican greenhouse, which houses succulents, is separated by an alley from the Australian greenhouse, which hosts plants from that country. They were built between 1834 and 1836 by the architect Rohault de Fleury. Each of the two greenhouses is 20 meters by 12 meters in size. Their iron and glass structure was revolutionary for Paris, preceding by fifteen years the similar pavilions built by Victor Baltard for the Paris markets of Les Halles.[22][23]
A larger structure, the "Jardin d'hiver" (Winter Garden), covering 750 square meters, was designed by René Berger and completed in 1937. It features an Art Deco entrance, between two illuminated glass and iron pillars built for nighttime visits. The heating system keeps the interior temperature at 22 degrees Celsius year-round, creating a suitable environment for bananas, palms, giant bamboo, and other tropical plants. Its central feature, designed to create a more natural environment, is a fifteen-meter-high waterfall.[
The Alpine Garden was created in 1931, and is about three meters higher than the other parts of the garden. It is divided into two zones, connected by a tunnel. It contains several different microclimates, controlled by the water distribution, the orientation toward the sun, the type of soil and the distribution of the rocks. It is home to plants for Corsica, the Caucasus, North America and the Himalayas. The oldest plant is a pistachio tree, planted in about 1700. This tree was the subject of research by the botanist Sebastien Vaillant in the 18th century which confirmed the sexuality of plants. Another ancient tree found there is the metasequoia, or dawn redwood, a primitive conifer.
A large section alongside the formal garden, with an entrance on the Allee Bequrerel, belongs to the School of Botany, and is dedicated to plants that have medicinal or economic uses. It was originally created in the 18th century, and now has over three thousand eight hundred specimens, organised by genus and family. Regular tours my museum guides are given of this section. One of its special attractions is the "Pinus nigra" or black pine, of the variety Laricio, from Corsica, which was planted in the garden by Jussieu in the 1770s.
The small garden is placed directly behind the Winter Garden greenhouse. Its prominent features are a large platane tree from the Orient, planted by Buffon in 1785, and a Ginkgo biloba, a tree originating in China considered a living fossil, since traces show that these trees existed in the Second Era of living things, as defined by botanists. It was planted in 1811.
In the center of the garden is monument to the botanist Bernardin de Saint-Pierre. the last director of the garden named by the King before the French Revolution, and the creator of the menagerie. He is better known in France as the author of a well-known romantic movel, "Paul et Virginie", published in 1788.
The Grand Labyrinth features a winding path to the top of the Butte Copeaux, a hill overlooking the garden. It was originally created under Louis XIII, then redone in its present form under Louis XVI, on the site of an old garbage dump. At the beginning of the upward path is a Cedar of Lebanon, planted in 1734 by Jussieu, with a trunk four meters in circumference. The butte was largely planted with trees from the Mediterranean, including an old erable tree from Crete planted in 1702 and still in place. including from in it is topped by a picturesque 18th-century cast-iron viewing platform, the oldest work of iron architecture in Paris. The labyrinth was created under Louis XIII, then redone by the garden director Buffon for Louis XVI.
At the top is a neoclassical viewing platform called the Gloriette de Buffon. It was made of cast iron, bronze and copper in 1786-87, using metal from the foundry owned by Buffon. It is considered the oldest metallic structure in Paris.[26] The eight iron columns carry a roof in the shape of a Chinese hat, topped by a lantern with a frieze decorated with swastikas a popular motif in the period. The top is inscribed with a tribute to Louis XVI, honouring his "justice, humanity, and munificence", as well as a quotation from Bouffon, in Latin, translated; "I only count the hours without clouds". It was originally equipped with a precise clock which chimed exactly at noon, but it disappeared in 1795.[26]
Nearby is the Lion Fountain, built in 1834 into the wall of a former reservoir. It is decorated with two bronze lions made in 1863 by the noted animal sculptor Henri Jacquemart.
The Menagerie is the second-oldest public zoo in the world still in operation (following the Tiergarten Schönbrunn in Vienna, Austria), founded in 1752.[27] It was laid out in its current form between 1798 and 1836, and occupies 5.5 hectares (13.6 acres). Besides displaying and studying animals, it has the mission, in cooperation with the zoos of other European cities, to preserve the genetic pool of certain endangered species, with the longer-term goal of trying to re-introduce some of these species into nature.[26]
The menagerie, in the style of 19th century zoos, is composed of a series of fenced areas, separated by paths, each with "Fabriques" or shelters in pictureesque styles, ranging from rustic to Art Deco. The largest building is the rotunda, built of brick and stone between 1804 and 1812, which unites five separate structures. Its form is said to have been inspired by the medal of the Legion of Honor. It was restored in 1988. It formerly contained the large animals of the collection, including the elephants and the famous giraffe given to King Charles X of France, which lived there for twenty-seven years. The trenches around the rotunda were part of the residence of bears. In 1934, most of the large animals were moved to the new zoo in the Bois de Vincennes, and now the building is used mainly for events and receptions.
The major structures in the Menagerie include the neoclassical Grand Volerie, built for flying animals by Louis-Jules André, the designer of the garden's central building, the Gallery of Evolution. It was built in 1888 of iron, stone and wood, in an oval form. Like the main building of the gardens, it features two neoclassical lantern towers. The Palace of Reptiles is also a work of André. It was built between 1870 and 1874. Its decoration includes a bronze statue of "The Snake Charmer" from 1862.
The Vivarium is a gallery by Emmanuel Pontremoli from 1926; it is a modernist update of a Classical Greek villa, with an Art Deco portico dating from 1926. Other notable buildings include the Art Deco Ape House from 1934, a ceramic-covered oval building with the cages on the exterior. In 1934, the apes were transferred to Vincennes.
The garden has a large collection of fossil plants, collected from around the world. Some of them are displayed in the greenhouses of the garden.
The Maison de l'Intendance or Maison de Bouffon, located the entrance to the garden at 36 Rue Geoffroy-Saint-Hilaire, was the residence of the Georges-Louis Leclerc, Comte de Buffon, the industrialist, naturalist, and director and chief creator of the gardens from 1739 to his death in 1788. It became part of the garden in 1777–79. (not open to public).[14]
The Cuvier House, next to the Gallery of Comparative Anatomy, was the residence of the scientist Georges Cuvier until his death in 1832. Cuvier was one of the founders of Paleontology, and the first to identify the skeleton of a mastodon as a prehistoric animal. Its facade displays his motto in Latin "The "Transibunt et augebitur scientia" ("The Hours Pass and science progresses"). The house was also the place where, in 1896, Henri Becquerel carried out the experiment in 1893 which led to the discovery of uranium. This event is marked by plaque on the facade. (not open to public).[29]
The Cuvier Fountain is across the street from the garden at the intersection of Rue Linné and Rue Cuvier, across the street from the very decorative wrought iron gates of the garden. The fountain honors George Cuvier, considered the father of comparative anatomy, with his statue surrounded by a varied collection of animals. It was built by the park architect Vigoureux and the sculptor Jean-Jacques Feuchère in 1840.
The Amphitheater near Rue Cuvier in the northwest corner, was constructed in 1787-88 in the garden of the Hôtel de Magny on Rue Cuvier. It was built under the direction of Buffon as a venue for lectures on natural science and the discoveries in the gardens. It was built in a purely neoclassical, or Paladian style. The frontons are decorated with 18th century sculpture depicting the natural sciences. The building was extensively restored in 2002–2003. A large stone vase in front of the amphitheater is a vestige of the Royal Abbey of Saint-Victor, which occupied the site of the amphitheater, and was destroyed during the French Revolution.[29]
The Pavilion of New Converts, in the northwest corner of the garden on the Allée Chevreul, is a vestige of the Convent of New Converts, founded in 1622 by Father Hyacinth of Paris and moved to the site in 1656. It was built to shelter Protestant converts to Catholicism. The surviving north facade, with a fronton in the Louis XIV style, contained the refectory, a parlour and bedrooms. After the French Revolution it became part of the gardens. It was the residence and laboratory of a director of the museum for 28 years, the chemist Eugene Chevreul, who died there in 1899 at the age of 103. Chevreul developed the use of color wheels or chromatic circles to resolve the definition of colors. His theory of colors was used at the Gobelins Manufactory of tapestries, where his laboratory was located, and inspired the palette of colors used by Eugène Delacroix. A statue of Chevreul is placed in the Carré Chevreul in the gardens.[29]
The hôtel de Magny at 57 Rue Cuvier is the administration building of the gardens. It was built in about 1700 under Louis XIV as a residence, designed by the royal architect Pierre Bullet, whose works included the Porte Saint-Martin and mansions in Le Marais and Place Vendôme After the Revolution, it turned into a boarding school; the celebrated actor Talma was one of the students. The house and estates were purchased, by Buffon in 1787 to enlarge the gardens (not open to the public).
The Paris Zoological Park was created in 1934 in the Bois de Vincennes, as space in menagerie of the Jardin des Plantes became scarce. It is administered, like the Jardin des Plantes, by the Museum of Natural History. New environments were created there for the larger mammals, including the giraffes, elephants, and hippopotamus. The new zoo covers 14.5 hectares (36 acres). The centrepiece is a large artificial rock, 65 meters (213 feet) high. It also includes a large greenhouse with 4000 square meters (43,000 square feet) of plantations, simulating a tropical rain forest.
The Parc des Clères in the Normandy specialises in birds and certain quadrupeds, including kangaroos and cervids.
The Arboretum de Chèvreloup, located near Versailles was founded in 1927. It covers 222 hectares, and has species raised from seeds collected from botanical gardens around the world. it focuses particularly upon
The Jardin botanique exotique de Menton, is located near Menton in the Alpes-Maritimes province. It specialises in tropical plants and those from the Mediterranean climate.
The Animal Park of la Haute Touche, between Sologne and Berry, specialises in reproducing endangered species in a large natural setting.
The Alpine Garden of Jaysinia at Samoëns in Haut-Savoie specialises in high-altitude plants from around the world, particularly from the Alps.
Paris is the capital and most populous city of France. With an official estimated population of 2,102,650 residents as of 1 January 2023[2] in an area of more than 105 km2 (41 sq mi) Paris is the fourth-most populated city in the European Union and the 30th most densely populated city in the world in 2022. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, culture, fashion, and gastronomy. For its leading role in the arts and sciences, as well as its early and extensive system of street lighting, in the 19th century, it became known as the City of Light.
The City of Paris is the centre of the Île-de-France region, or Paris Region, with an official estimated population of 12,271,794 inhabitants on 1 January 2023, or about 19% of the population of France, The Paris Region had a GDP of €765 billion (US$1.064 trillion, PPP) in 2021, the highest in the European Union. According to the Economist Intelligence Unit Worldwide Cost of Living Survey, in 2022, Paris was the city with the ninth-highest cost of living in the world.
Paris is a major railway, highway, and air-transport hub served by two international airports: Charles de Gaulle Airport (the third-busiest airport in Europe) and Orly Airport. Opened in 1900, the city's subway system, the Paris Métro, serves 5.23 million passengers daily; it is the second-busiest metro system in Europe after the Moscow Metro. Gare du Nord is the 24th-busiest railway station in the world and the busiest outside Japan, with 262 million passengers in 2015. Paris has one of the most sustainable transportation systems and is one of the only two cities in the world that received the Sustainable Transport Award twice.
Paris is especially known for its museums and architectural landmarks: the Louvre received 8.9. million visitors in 2023, on track for keeping its position as the most-visited art museum in the world. The Musée d'Orsay, Musée Marmottan Monet and Musée de l'Orangerie are noted for their collections of French Impressionist art. The Pompidou Centre Musée National d'Art Moderne, Musée Rodin and Musée Picasso are noted for their collections of modern and contemporary art. The historical district along the Seine in the city centre has been classified as a UNESCO World Heritage Site since 1991.
Paris hosts several United Nations organizations including UNESCO, and other international organizations such as the OECD, the OECD Development Centre, the International Bureau of Weights and Measures, the International Energy Agency, the International Federation for Human Rights, along with European bodies such as the European Space Agency, the European Banking Authority and the European Securities and Markets Authority. The football club Paris Saint-Germain and the rugby union club Stade Français are based in Paris. The 80,000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the neighbouring commune of Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros. The city hosted the Olympic Games in 1900 and 1924, and will host the 2024 Summer Olympics. The 1938 and 1998 FIFA World Cups, the 2019 FIFA Women's World Cup, the 2007 Rugby World Cup, as well as the 1960, 1984 and 2016 UEFA European Championships were also held in the city. Every July, the Tour de France bicycle race finishes on the Avenue des Champs-Élysées in Paris.
The Parisii, a sub-tribe of the Celtic Senones, inhabited the Paris area from around the middle of the 3rd century BC. One of the area's major north–south trade routes crossed the Seine on the île de la Cité, which gradually became an important trading centre. The Parisii traded with many river towns (some as far away as the Iberian Peninsula) and minted their own coins.
The Romans conquered the Paris Basin in 52 BC and began their settlement on Paris's Left Bank. The Roman town was originally called Lutetia (more fully, Lutetia Parisiorum, "Lutetia of the Parisii", modern French Lutèce). It became a prosperous city with a forum, baths, temples, theatres, and an amphitheatre.
By the end of the Western Roman Empire, the town was known as Parisius, a Latin name that would later become Paris in French. Christianity was introduced in the middle of the 3rd century AD by Saint Denis, the first Bishop of Paris: according to legend, when he refused to renounce his faith before the Roman occupiers, he was beheaded on the hill which became known as Mons Martyrum (Latin "Hill of Martyrs"), later "Montmartre", from where he walked headless to the north of the city; the place where he fell and was buried became an important religious shrine, the Basilica of Saint-Denis, and many French kings are buried there.
Clovis the Frank, the first king of the Merovingian dynasty, made the city his capital from 508. As the Frankish domination of Gaul began, there was a gradual immigration by the Franks to Paris and the Parisian Francien dialects were born. Fortification of the Île de la Cité failed to avert sacking by Vikings in 845, but Paris's strategic importance—with its bridges preventing ships from passing—was established by successful defence in the Siege of Paris (885–886), for which the then Count of Paris (comte de Paris), Odo of France, was elected king of West Francia. From the Capetian dynasty that began with the 987 election of Hugh Capet, Count of Paris and Duke of the Franks (duc des Francs), as king of a unified West Francia, Paris gradually became the largest and most prosperous city in France.
By the end of the 12th century, Paris had become the political, economic, religious, and cultural capital of France.[36] The Palais de la Cité, the royal residence, was located at the western end of the Île de la Cité. In 1163, during the reign of Louis VII, Maurice de Sully, bishop of Paris, undertook the construction of the Notre Dame Cathedral at its eastern extremity.
After the marshland between the river Seine and its slower 'dead arm' to its north was filled in from around the 10th century, Paris's cultural centre began to move to the Right Bank. In 1137, a new city marketplace (today's Les Halles) replaced the two smaller ones on the Île de la Cité and Place de Grève (Place de l'Hôtel de Ville). The latter location housed the headquarters of Paris's river trade corporation, an organisation that later became, unofficially (although formally in later years), Paris's first municipal government.
In the late 12th century, Philip Augustus extended the Louvre fortress to defend the city against river invasions from the west, gave the city its first walls between 1190 and 1215, rebuilt its bridges to either side of its central island, and paved its main thoroughfares. In 1190, he transformed Paris's former cathedral school into a student-teacher corporation that would become the University of Paris and would draw students from all of Europe.
With 200,000 inhabitants in 1328, Paris, then already the capital of France, was the most populous city of Europe. By comparison, London in 1300 had 80,000 inhabitants. By the early fourteenth century, so much filth had collected inside urban Europe that French and Italian cities were naming streets after human waste. In medieval Paris, several street names were inspired by merde, the French word for "shit".
During the Hundred Years' War, Paris was occupied by England-friendly Burgundian forces from 1418, before being occupied outright by the English when Henry V of England entered the French capital in 1420; in spite of a 1429 effort by Joan of Arc to liberate the city, it would remain under English occupation until 1436.
In the late 16th-century French Wars of Religion, Paris was a stronghold of the Catholic League, the organisers of 24 August 1572 St. Bartholomew's Day massacre in which thousands of French Protestants were killed. The conflicts ended when pretender to the throne Henry IV, after converting to Catholicism to gain entry to the capital, entered the city in 1594 to claim the crown of France. This king made several improvements to the capital during his reign: he completed the construction of Paris's first uncovered, sidewalk-lined bridge, the Pont Neuf, built a Louvre extension connecting it to the Tuileries Palace, and created the first Paris residential square, the Place Royale, now Place des Vosges. In spite of Henry IV's efforts to improve city circulation, the narrowness of Paris's streets was a contributing factor in his assassination near Les Halles marketplace in 1610.
During the 17th century, Cardinal Richelieu, chief minister of Louis XIII, was determined to make Paris the most beautiful city in Europe. He built five new bridges, a new chapel for the College of Sorbonne, and a palace for himself, the Palais-Cardinal. After Richelieu's death in 1642, it was renamed the Palais-Royal.
Due to the Parisian uprisings during the Fronde civil war, Louis XIV moved his court to a new palace, Versailles, in 1682. Although no longer the capital of France, arts and sciences in the city flourished with the Comédie-Française, the Academy of Painting, and the French Academy of Sciences. To demonstrate that the city was safe from attack, the king had the city walls demolished and replaced with tree-lined boulevards that would become the Grands Boulevards. Other marks of his reign were the Collège des Quatre-Nations, the Place Vendôme, the Place des Victoires, and Les Invalides.
18th and 19th centuries
Empire, and Haussmann's renovation of Paris
Paris grew in population from about 400,000 in 1640, to 650,000 in 1780. A new boulevard named the Champs-Élysées extended the city west to Étoile, while the working-class neighbourhood of the Faubourg Saint-Antoine on the eastern side of the city grew increasingly crowded with poor migrant workers from other regions of France.
Paris was the centre of an explosion of philosophic and scientific activity, known as the Age of Enlightenment. Diderot and d'Alembert published their Encyclopédie in 1751, and the Montgolfier Brothers launched the first manned flight in a hot air balloon on 21 November 1783. Paris was the financial capital of continental Europe, and the primary European centre of book publishing, fashion and the manufacture of fine furniture and luxury goods.
In the summer of 1789, Paris became the centre stage of the French Revolution. On 14 July, a mob seized the arsenal at the Invalides, acquiring thousands of guns, and stormed the Bastille, which was a principal symbol of royal authority. The first independent Paris Commune, or city council, met in the Hôtel de Ville and elected a Mayor, the astronomer Jean Sylvain Bailly, on 15 July.
Louis XVI and the royal family were brought to Paris and incarcerated in the Tuileries Palace. In 1793, as the revolution turned increasingly radical, the king, queen and mayor were beheaded by guillotine in the Reign of Terror, along with more than 16,000 others throughout France. The property of the aristocracy and the church was nationalised, and the city's churches were closed, sold or demolished. A succession of revolutionary factions ruled Paris until 9 November 1799 (coup d'état du 18 brumaire), when Napoleon Bonaparte seized power as First Consul.
The population of Paris had dropped by 100,000 during the Revolution, but after 1799 it surged with 160,000 new residents, reaching 660,000 by 1815. Napoleon replaced the elected government of Paris with a prefect that reported directly to him. He began erecting monuments to military glory, including the Arc de Triomphe, and improved the neglected infrastructure of the city with new fountains, the Canal de l'Ourcq, Père Lachaise Cemetery and the city's first metal bridge, the Pont des Arts.
The Eiffel Tower, under construction in November 1888, startled Parisians—and the world—with its modernity.
During the Restoration, the bridges and squares of Paris were returned to their pre-Revolution names; the July Revolution in 1830 (commemorated by the July Column on the Place de la Bastille) brought to power a constitutional monarch, Louis Philippe I. The first railway line to Paris opened in 1837, beginning a new period of massive migration from the provinces to the city. In 1848, Louis-Philippe was overthrown by a popular uprising in the streets of Paris. His successor, Napoleon III, alongside the newly appointed prefect of the Seine, Georges-Eugène Haussmann, launched a huge public works project to build wide new boulevards, a new opera house, a central market, new aqueducts, sewers and parks, including the Bois de Boulogne and Bois de Vincennes. In 1860, Napoleon III annexed the surrounding towns and created eight new arrondissements, expanding Paris to its current limits.
During the Franco-Prussian War (1870–1871), Paris was besieged by the Prussian Army. Following several months of blockade, hunger, and then bombardment by the Prussians, the city was forced to surrender on 28 January 1871. After seizing power in Paris on 28 March, a revolutionary government known as the Paris Commune held power for two months, before being harshly suppressed by the French army during the "Bloody Week" at the end of May 1871.
In the late 19th century, Paris hosted two major international expositions: the 1889 Universal Exposition, which featured the new Eiffel Tower, was held to mark the centennial of the French Revolution; and the 1900 Universal Exposition gave Paris the Pont Alexandre III, the Grand Palais, the Petit Palais and the first Paris Métro line. Paris became the laboratory of Naturalism (Émile Zola) and Symbolism (Charles Baudelaire and Paul Verlaine), and of Impressionism in art (Courbet, Manet, Monet, Renoir).
20th and 21st centuries
World War, Paris between the Wars (1919–1939), Paris in World War II, and History of Paris (1946–2000)
By 1901, the population of Paris had grown to about 2,715,000. At the beginning of the century, artists from around the world including Pablo Picasso, Modigliani, and Henri Matisse made Paris their home. It was the birthplace of Fauvism, Cubism and abstract art, and authors such as Marcel Proust were exploring new approaches to literature.
During the First World War, Paris sometimes found itself on the front line; 600 to 1,000 Paris taxis played a small but highly important symbolic role in transporting 6,000 soldiers to the front line at the First Battle of the Marne. The city was also bombed by Zeppelins and shelled by German long-range guns. In the years after the war, known as Les Années Folles, Paris continued to be a mecca for writers, musicians and artists from around the world, including Ernest Hemingway, Igor Stravinsky, James Joyce, Josephine Baker, Eva Kotchever, Henry Miller, Anaïs Nin, Sidney Bechet and Salvador Dalí.
In the years after the peace conference, the city was also home to growing numbers of students and activists from French colonies and other Asian and African countries, who later became leaders of their countries, such as Ho Chi Minh, Zhou Enlai and Léopold Sédar Senghor.
General Charles de Gaulle on the Champs-Élysées celebrating the liberation of Paris, 26 August 1944
On 14 June 1940, the German army marched into Paris, which had been declared an "open city". On 16–17 July 1942, following German orders, the French police and gendarmes arrested 12,884 Jews, including 4,115 children, and confined them during five days at the Vel d'Hiv (Vélodrome d'Hiver), from which they were transported by train to the extermination camp at Auschwitz. None of the children came back. On 25 August 1944, the city was liberated by the French 2nd Armoured Division and the 4th Infantry Division of the United States Army. General Charles de Gaulle led a huge and emotional crowd down the Champs Élysées towards Notre Dame de Paris, and made a rousing speech from the Hôtel de Ville.
In the 1950s and the 1960s, Paris became one front of the Algerian War for independence; in August 1961, the pro-independence FLN targeted and killed 11 Paris policemen, leading to the imposition of a curfew on Muslims of Algeria (who, at that time, were French citizens). On 17 October 1961, an unauthorised but peaceful protest demonstration of Algerians against the curfew led to violent confrontations between the police and demonstrators, in which at least 40 people were killed. The anti-independence Organisation armée secrète (OAS) carried out a series of bombings in Paris throughout 1961 and 1962.
In May 1968, protesting students occupied the Sorbonne and put up barricades in the Latin Quarter. Thousands of Parisian blue-collar workers joined the students, and the movement grew into a two-week general strike. Supporters of the government won the June elections by a large majority. The May 1968 events in France resulted in the break-up of the University of Paris into 13 independent campuses. In 1975, the National Assembly changed the status of Paris to that of other French cities and, on 25 March 1977, Jacques Chirac became the first elected mayor of Paris since 1793. The Tour Maine-Montparnasse, the tallest building in the city at 57 storeys and 210 m (689 ft) high, was built between 1969 and 1973. It was highly controversial, and it remains the only building in the centre of the city over 32 storeys high. The population of Paris dropped from 2,850,000 in 1954 to 2,152,000 in 1990, as middle-class families moved to the suburbs. A suburban railway network, the RER (Réseau Express Régional), was built to complement the Métro; the Périphérique expressway encircling the city, was completed in 1973.
Most of the postwar presidents of the Fifth Republic wanted to leave their own monuments in Paris; President Georges Pompidou started the Centre Georges Pompidou (1977), Valéry Giscard d'Estaing began the Musée d'Orsay (1986); President François Mitterrand had the Opéra Bastille built (1985–1989), the new site of the Bibliothèque nationale de France (1996), the Arche de la Défense (1985–1989) in La Défense, as well as the Louvre Pyramid with its underground courtyard (1983–1989); Jacques Chirac (2006), the Musée du quai Branly.
In the early 21st century, the population of Paris began to increase slowly again, as more young people moved into the city. It reached 2.25 million in 2011. In March 2001, Bertrand Delanoë became the first socialist mayor. He was re-elected in March 2008. In 2007, in an effort to reduce car traffic, he introduced the Vélib', a system which rents bicycles. Bertrand Delanoë also transformed a section of the highway along the Left Bank of the Seine into an urban promenade and park, the Promenade des Berges de la Seine, which he inaugurated in June 2013.
In 2007, President Nicolas Sarkozy launched the Grand Paris project, to integrate Paris more closely with the towns in the region around it. After many modifications, the new area, named the Metropolis of Grand Paris, with a population of 6.7 million, was created on 1 January 2016. In 2011, the City of Paris and the national government approved the plans for the Grand Paris Express, totalling 205 km (127 mi) of automated metro lines to connect Paris, the innermost three departments around Paris, airports and high-speed rail (TGV) stations, at an estimated cost of €35 billion.The system is scheduled to be completed by 2030.
In January 2015, Al-Qaeda in the Arabian Peninsula claimed attacks across the Paris region. 1.5 million people marched in Paris in a show of solidarity against terrorism and in support of freedom of speech. In November of the same year, terrorist attacks, claimed by ISIL, killed 130 people and injured more than 350.
On 22 April 2016, the Paris Agreement was signed by 196 nations of the United Nations Framework Convention on Climate Change in an aim to limit the effects of climate change below 2 °C.
Candid street shot Barcelona, Spain.
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In the context of some religions, temptation is the inclination to sin. Temptation also describes the coaxing or inducing a person into committing such an act, by manipulation or otherwise of curiosity, desire or fear of loss.
The temptation of Christ is detailed in the Gospels of Matthew, Mark, and Luke. According to these texts, after being baptised by John the Baptist, Jesus fasted for forty days and nights in the Judaean Desert. During this time, Satan appeared to Jesus and tried to tempt him. Jesus having refused each temptation, the devil then departed and Jesus returned to Galilee.
The devil tempts Jesus to:
Make bread out of stones to relieve his own hunger.
Jump from a pinnacle and rely on angels to break his fall.
Worship the devil in return for all the kingdoms of the world.
Fasting traditionally presaged a great spiritual struggle. Elijah and Moses in the Old Testament fasted 40 days and nights, and thus Jesus doing the same invites comparison to these events. In Judaism, "the practice of fasting connected the body and its physical needs with less tangible values, such as self-denial, and repentance."
At the time, 40 was less a specific number and more a general expression for any large figure.
Fasting may not mean a complete abstinence from food; consequently, Jesus may have been surviving on the sparse food that could be obtained in the desert.
Now the science: --
Did Jesus see Satan or was it a result of confusion due to starvation ?
Unlikely, the human body is cleverly designed to cope with food shortages and consequent starvation.
The human body can go without oxygen for about five to ten minutes, and about three to eight days without water. But remarkably, people have been known to live upwards of 70 days without food.
The human starvation response is unique among animals in that human brains do not require the ingestion of glucose to function. During starvation, less than half the energy used by the brain comes from metabolised glucose. Because the human brain can use ketone bodies as major fuel sources, the body is not forced to break down skeletal muscles at a high rate, thereby maintaining both cognitive function and mobility for up to several weeks. This response is extremely important in human evolution and allowed for humans to continue to find food effectively even in the face of prolonged starvation
Ordinarily, the body responds to reduced energy intake by burning fat reserves and consuming muscle and other tissues. Specifically, the body burns fat after first exhausting the contents of the digestive tract along with glycogen reserves stored in muscle and liver cells. After prolonged periods of starvation, the body will utilise the proteins within muscle tissue as a fuel source. People who practise fasting on a regular basis, such as those adhering to energy restricted diets, can prime their bodies to abstain from food while reducing the amount of muscle burned.
During the Irish Hunger Strikes of 1981, for example, ten men survived without food (drinking only water) for periods ranging from 46 to 73 days.
To think that human life can be sustained for that length of time without food is nothing short of remarkable — a feat of biological engineering that's the result of millions of years of painstaking and painful evolution,
(Well that or God had a pretty good design team working on humans).
PS:
Lamb of God (sometimes abbreviated as LoG) is an American heavy metal band from Richmond, Virginia. Formed in 1994
Springtime in Interior Alaska! The wood frogs are awake and mating.
Wood frogs have one of the more impressive survival strategies. In the fall they convert the sugars in their body into glycogen to coat their cell walls so they will not rupture when they freeze. They then borrow into mud or leave litter and freeze into a frogcycle.
They live for 5 years so they perform this magic 5 times.
This is some spawn of fertilized eggs that will soon turn into tadpoles.
I did the Peacocks and Kites 300km Audax from Cardiff on Saturday. It was my first solo Audax, my first long ride on the Graft, and I ended up being joint first person back. I had a very nice time.
It started at 5.00am with a thunder storm and torrential rain soaking us to the skin. The sun came out by midday but I was pretty wet so I was glad to press on and keep myself warm. I didn't stop at the controls any longer than it took to nip to the loo, get my card stamped, and fill my bottles, and it saved me loads of time. Everyone was stopping to fuel up on breafast and cake but I just ate from my bag on my bars as I went. I had a 4 egg omelette for breakfast before I left at 4.30am and then througout the day I munched my way though 4 sausages, 60g cheese, 150g cashew nuts, and 25g 85% dark chocolate. Nothing else. I drank 10L of water most with zero calorie salt magnesium tablets in. I wasn't hungry and I felt good. I measured my ketones up at 3.9mmol at lunch time so I knew my body was working hard to keep me well fuelled on fat. The hills were pretty tiring and my legs were empty of glycogen by the time I got to the ridiculously steep climb around 250km. I made it up without getting off, just, then I punctured coming down the other side. Gary wasn't far behind and came past just as I was setting off. I caught up with him and we rode back together, pulling down the gradual hill in to a slight headwind all the way back to Cardiff, our chains both squeeling away since the lube washed off at around 200km.
Tracklog on Strava:
On the way to Mt Kosciusko a group of runners hit the track as well.
As one can see it was not very warm at all nether the less this one had only shorts and shoes on! Though guy!
Runner's High
Another widely publicized effect of endorphin production is the so-called "runner's high", which is said to occur when strenuous exercise takes a person over a threshold that activates endorphin production. Endorphins are released during long, continuous workouts, when the level of intensity is between moderate and high, and breathing is difficult. This also corresponds with the time that muscles use up their stored glycogen. Workouts that are most likely to produce endorphins include running, swimming, cross-country skiing, long distance rowing, bicycling, weight lifting, aerobics, or playing a sport such as basketball, rugby, or American football.
(Source: http://en.wikipedia.org/wiki/Endorphin)
(Foto used in the artikle NowPublic: "Yes, Running Can Make You High")
A fungus (pl.: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the traditional eukaryotic kingdoms, along with Animalia, Plantae and either Protista or Protozoa and Chromista.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (i.e. they form a monophyletic group), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology (from the Greek μύκης mykes, mushroom). In the past mycology was regarded as a branch of botany, although it is now known that fungi are genetically more closely related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and also parasites. They may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment. They have long been used as a direct source of human food, in the form of mushrooms and truffles; as a leavening agent for bread; and in the fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological pesticides to control weeds, plant diseases, and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals, including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g., rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.
The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of the fungus kingdom, which has been estimated at 2.2 million to 3.8 million species. Of these, only about 148,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christiaan Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the first decade of the 21st century have helped reshape the classification within the fungi kingdom, which is divided into one subkingdom, seven phyla, and ten subphyla.
Etymology
The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos (σφόγγος 'sponge'), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm ('sponge') and Schimmel ('mold').
The word mycology is derived from the Greek mykes (μύκης 'mushroom') and logos (λόγος 'discourse'). It denotes the scientific study of fungi. The Latin adjectival form of "mycology" (mycologicæ) appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon. The word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. also refers to mycology as the study of fungi.
A group of all the fungi present in a particular region is known as mycobiota (plural noun, no singular). The term mycota is often used for this purpose, but many authors use it as a synonym of Fungi. The word funga has been proposed as a less ambiguous term morphologically similar to fauna and flora. The Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN) in August 2021 asked that the phrase fauna and flora be replaced by fauna, flora, and funga.
Characteristics
Fungal hyphae cells
Hyphal wall
Septum
Mitochondrion
Vacuole
Ergosterol crystal
Ribosome
Nucleus
Endoplasmic reticulum
Lipid body
Plasma membrane
Spitzenkörper
Golgi apparatus
Fungal cell cycle showing Dikaryons typical of Higher Fungi
Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Although inaccurate, the common misconception that fungi are plants persists among the general public due to their historical classification, as well as several similarities. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era). Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:
With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type. They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals).
With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.
With plants: Fungi have a cell wall and vacuoles. They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.
With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.
The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper. Both fungi and oomycetes grow as filamentous hyphal cells. In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells. There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.
In common with some plant and animal species, more than one hundred fungal species display bioluminescence.
Unique features:
Some species grow as unicellular yeasts that reproduce by budding or fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.
The fungal cell wall is made of a chitin-glucan complex; while glucans are also found in plants and chitin in the exoskeleton of arthropods, fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.
A whitish fan or funnel-shaped mushroom growing at the base of a tree.
Omphalotus nidiformis, a bioluminescent mushroom
Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs, which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks. Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure that fungi and animals do not have. Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants. Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.
Diversity
Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Some can survive the intense UV and cosmic radiation encountered during space travel. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans, parasites that have been responsible for a worldwide decline in amphibian populations. These organisms spend part of their life cycle as a motile zoospore, enabling them to propel itself through water and enter their amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.
As of 2020, around 148,000 species of fungi have been described by taxonomists, but the global biodiversity of the fungus kingdom is not fully understood. A 2017 estimate suggests there may be between 2.2 and 3.8 million species The number of new fungi species discovered yearly has increased from 1,000 to 1,500 per year about 10 years ago, to about 2000 with a peak of more than 2,500 species in 2016. In the year 2019, 1882 new species of fungi were described, and it was estimated that more than 90% of fungi remain unknown The following year, 2905 new species were described—the highest annual record of new fungus names. In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy. Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.
Mycology
Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.
The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus). Ancient peoples have used fungi as food sources—often unknowingly—for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.
History
Mycology became a systematic science after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera. Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated. Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christiaan Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. In the 20th and 21st centuries, advances in biochemistry, genetics, molecular biology, biotechnology, DNA sequencing and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.
Morphology
Microscopic structures
Monochrome micrograph showing Penicillium hyphae as long, transparent, tube-like structures a few micrometres across. Conidiophores branch out laterally from the hyphae, terminating in bundles of phialides on which spherical condidiophores are arranged like beads on a string. Septa are faintly visible as dark lines crossing the hyphae.
An environmental isolate of Penicillium
Hypha
Conidiophore
Phialide
Conidia
Septa
Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 µm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastomosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized. Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota. Coenocytic hyphae are in essence multinucleate supercells.
Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla,[63] and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.
Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella. Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.
Macroscopic structures
Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups. Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.
The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells. The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.
Growth and physiology
Time-lapse photography sequence of a peach becoming progressively discolored and disfigured
Mold growth covering a decaying peach. The frames were taken approximately 12 hours apart over a period of six days.
The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues.[71] The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi).[71] The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.
The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol. Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients. The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha. Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi, or growth by volume expansion during the development of mushroom stipes and other large organs. Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.
Fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known. This process might bear similarity to CO2 fixation via visible light, but instead uses ionizing radiation as a source of energy.
Reproduction
Two thickly stemmed brownish mushrooms with scales on the upper surface, growing out of a tree trunk
Polyporus squamosus
Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph (sexual reproduction) and the anamorph (asexual reproduction). Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.
Asexual reproduction
Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction. The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle. Deuteromycota (alternatively known as Deuteromycetes, conidial fungi, or mitosporic fungi) is not an accepted taxonomic clade and is now taken to mean simply fungi that lack a known sexual stage.
Sexual reproduction
See also: Mating in fungi and Sexual selection in fungi
Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies. Mating experiments between fungal isolates may identify species on the basis of biological species concepts. The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Fungi employ two mating systems: heterothallic species allow mating only between individuals of the opposite mating type, whereas homothallic species can mate, and sexually reproduce, with any other individual or itself.
Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).
In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook (crozier) at the hyphal septum. During cell division, the formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.
Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment. A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis. The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).
In fungi formerly classified as Zygomycota, haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.
Spore dispersal
The spores of most of the researched species of fungi are transported by wind. Such species often produce dry or hydrophobic spores that do not absorb water and are readily scattered by raindrops, for example. In other species, both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances.
Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection. For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g; the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below. Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The hydnoid fungi (tooth fungi) produce spores on pendant, tooth-like or spine-like projections. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies. Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.
Homothallism
In homothallic sexual reproduction, two haploid nuclei derived from the same individual fuse to form a zygote that can then undergo meiosis. Homothallic fungi include species with an Aspergillus-like asexual stage (anamorphs) occurring in numerous different genera, several species of the ascomycete genus Cochliobolus, and the ascomycete Pneumocystis jirovecii. The earliest mode of sexual reproduction among eukaryotes was likely homothallism, that is, self-fertile unisexual reproduction.
Other sexual processes
Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells. The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization and is likely required for hybridization between species, which has been associated with major events in fungal evolution.
Evolution
In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.
The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. The oldest fossilizied mycelium to be identified from its molecular composition is between 715 and 810 million years old. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.
In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).
Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.
Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess, the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary.
Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like "a massive compost heap".
Taxonomy
Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.
There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).
The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances.
The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. As of 2019, nine major lineages have been identified: Opisthosporidia, Chytridiomycota, Neocallimastigomycota, Blastocladiomycota, Zoopagomycotina, Mucoromycota, Glomeromycota, Ascomycota and Basidiomycota.
Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species). Previously considered to be "primitive" protozoa, they are now thought to be either a basal branch of the Fungi, or a sister group–each other's closest evolutionary relative.
The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.
The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.
The Neocallimastigomycota were earlier placed in the phylum Chytridiomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites). They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.
Microscopic view of a layer of translucent grayish cells, some containing small dark-color spheres
Arbuscular mycorrhiza seen under microscope. Flax root cortical cells containing paired arbuscules.
Cross-section of a cup-shaped structure showing locations of developing meiotic asci (upper edge of cup, left side, arrows pointing to two gray cells containing four and two small circles), sterile hyphae (upper edge of cup, right side, arrows pointing to white cells with a single small circle in them), and mature asci (upper edge of cup, pointing to two gray cells with eight small circles in them)
Diagram of an apothecium (the typical cup-like reproductive structure of Ascomycetes) showing sterile tissues as well as developing and mature asci.
Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually. The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago. Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota. Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina. Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.
The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).
Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans.
Fungus-like organisms
Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to an ambiregnal, duplicated taxonomy.
Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and take in nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.
The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.
The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi. Alternatively, Rozella can be classified as a basal fungal group.
The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom. Many Actinomycetales (Actinomycetota), a group with many filamentous bacteria, were also long believed to be fungi.
Ecology
Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.
Symbiosis
Many fungi have important symbiotic relationships with organisms from most if not all kingdoms. These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.
With plants
Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.
A microscopic view of blue-stained cells, some with dark wavy lines in them
The dark filaments are hyphae of the endophytic fungus Epichloë coenophiala in the intercellular spaces of tall fescue leaf sheath tissue
The mycorrhizal symbiosis is ancient, dating back to at least 400 million years. It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients. The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks". A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont. Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes. Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.
With algae and cyanobacteria
A green, leaf-like structure attached to a tree, with a pattern of ridges and depression on the bottom surface
The lichen Lobaria pulmonaria, a symbiosis of fungal, algal, and cyanobacterial species
Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes. Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession, and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions. They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves. As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 27% of known fungi—more than 19,400 species—are lichenized. Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.
With insects
Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Chaetothyriales for several purposes: as a food source, as a structural component of their nests, and as a part of an ant/plant symbiosis in the domatia (tiny chambers in plants that house arthropods). Ambrosia beetles cultivate various species of fungi in the bark of trees that they infest. Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae. At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests. Termites on the African savannah are also known to cultivate fungi, and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts. Fungi growing in dead wood are essential for xylophagous insects (e.g. woodboring beetles). They deliver nutrients needed by xylophages to nutritionally scarce dead wood. Thanks to this nutritional enrichment the larvae of the woodboring insect is able to grow and develop to adulthood. The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.
A thin brown stick positioned horizontally with roughly two dozen clustered orange-red leaves originating from a single point in the middle of the stick. These orange leaves are three to four times larger than the few other green leaves growing out of the stick, and are covered on the lower leaf surface with hundreds of tiny bumps. The background shows the green leaves and branches of neighboring shrubs.
The plant pathogen Puccinia magellanicum (calafate rust) causes the defect known as witch's broom, seen here on a barberry shrub in Chile.
Gram stain of Candida albicans from a vaginal swab from a woman with candidiasis, showing hyphae, and chlamydospores, which are 2–4 µm in diameter.
Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae, tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease, Cryphonectria parasitica responsible for chestnut blight, and Phymatotrichopsis omnivora causing Texas Root Rot, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets. Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed). This same principle is applied to fungi-feeding parasites, including Asterotremella albida, which feeds on the fruit bodies of other fungi both while they are living and after they are dead.
Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma, and Pneumocystis. Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.
As targets of mycoparasites
Organisms that parasitize fungi are known as mycoparasitic organisms. About 300 species of fungi and fungus-like organisms, belonging to 13 classes and 113 genera, are used as biocontrol agents against plant fungal diseases. Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms. Fungi can also become the target of infection by mycoviruses.
Communication
Main article: Mycorrhizal networks
There appears to be electrical communication between fungi in word-like components according to spiking characteristics.
Possible impact on climate
According to a study published in the academic journal Current Biology, fungi can soak from the atmosphere around 36% of global fossil fuel greenhouse gas emissions.
Mycotoxins
(6aR,9R)-N-((2R,5S,10aS,10bS)-5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-2H-oxazolo[3,2-a] pyrrolo[2,1-c]pyrazin-2-yl)-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg] quinoline-9-carboxamide
Ergotamine, a major mycotoxin produced by Claviceps species, which if ingested can cause gangrene, convulsions, and hallucinations
Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea. Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.
Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi. Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory). Many fungal secondary metabolites (or derivatives) are used medically, as described under Human use below.
Pathogenic mechanisms
Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen's virulence. Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis. The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.
Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages. Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response. Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.
Human use
See also: Human interactions with fungi
Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres
Saccharomyces cerevisiae cells shown with DIC microscopy
The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. Methods have been developed for genetic engineering of fungi, enabling metabolic engineering of fungal species. For example, genetic modification of yeast species—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms. Fungi-based industries are sometimes considered to be a major part of a growing bioeconomy, with applications under research and development including use for textiles, meat substitution and general fungal biotechnology.
Therapeutic uses
Modern chemotherapeutics
Many species produce metabolites that are major sources of pharmacologically active drugs.
Antibiotics
Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties. Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria. Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.
Other
Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections, and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom. Psilocybin from fungi is investigated for therapeutic use and appears to cause global increases in brain network integration. Fungi produce compounds that inhibit viruses and cancer cells. Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan. In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.
Traditional medicine
Upper surface view of a kidney-shaped fungus, brownish-red with a lighter yellow-brown margin, and a somewhat varnished or shiny appearance
Two dried yellow-orange caterpillars, one with a curly grayish fungus growing out of one of its ends. The grayish fungus is roughly equal to or slightly greater in length than the caterpillar, and tapers in thickness to a narrow end.
The fungi Ganoderma lucidum (left) and Ophiocordyceps sinensis (right) are used in traditional medicine practices
Certain mushrooms are used as supposed therapeutics in folk medicine practices, such as traditional Chinese medicine. Mushrooms with a history of such use include Agaricus subrufescens, Ganoderma lucidum, and Ophiocordyceps sinensis.
Cultured foods
Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings. Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation. Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso while Rhizopus species are used for making tempeh. Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli. Quorn, a meat substitute, is made from Fusarium venenatum.
You can use creatine supplements if you are not getting enough in your diet. Creatine is usually fount in red meats, like steak, so that vegetarians or anyone who does not eat a lot of creatine filled foods may benefit from the use of these supplements. Glycogen, a carb is often achieved by carb-loading (like pasta) so taking creatine supplements will mean that you have to do less of this as well.
Creatine increases cardiovascular activity. When you take creatine supplements, you will most likely notice the effects of drugs in your anabolic workout. It can be a positive effect in your cardiovascular exercise routine as well. Creatine does help every bodybuilder to increase the amount of aerobic activity that you can do before getting winded so that you will be able to exercise longer and give it your all.
A fungus (pl.: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the traditional eukaryotic kingdoms, along with Animalia, Plantae and either Protista or Protozoa and Chromista.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (i.e. they form a monophyletic group), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology (from the Greek μύκης mykes, mushroom). In the past mycology was regarded as a branch of botany, although it is now known that fungi are genetically more closely related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and also parasites. They may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment. They have long been used as a direct source of human food, in the form of mushrooms and truffles; as a leavening agent for bread; and in the fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological pesticides to control weeds, plant diseases, and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals, including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g., rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.
The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of the fungus kingdom, which has been estimated at 2.2 million to 3.8 million species. Of these, only about 148,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christiaan Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the first decade of the 21st century have helped reshape the classification within the fungi kingdom, which is divided into one subkingdom, seven phyla, and ten subphyla.
Etymology
The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos (σφόγγος 'sponge'), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm ('sponge') and Schimmel ('mold').
The word mycology is derived from the Greek mykes (μύκης 'mushroom') and logos (λόγος 'discourse'). It denotes the scientific study of fungi. The Latin adjectival form of "mycology" (mycologicæ) appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon. The word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. also refers to mycology as the study of fungi.
A group of all the fungi present in a particular region is known as mycobiota (plural noun, no singular). The term mycota is often used for this purpose, but many authors use it as a synonym of Fungi. The word funga has been proposed as a less ambiguous term morphologically similar to fauna and flora. The Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN) in August 2021 asked that the phrase fauna and flora be replaced by fauna, flora, and funga.
Characteristics
Fungal hyphae cells
Hyphal wall
Septum
Mitochondrion
Vacuole
Ergosterol crystal
Ribosome
Nucleus
Endoplasmic reticulum
Lipid body
Plasma membrane
Spitzenkörper
Golgi apparatus
Fungal cell cycle showing Dikaryons typical of Higher Fungi
Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Although inaccurate, the common misconception that fungi are plants persists among the general public due to their historical classification, as well as several similarities. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era). Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:
With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type. They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals).
With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.
With plants: Fungi have a cell wall and vacuoles. They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.
With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.
The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper. Both fungi and oomycetes grow as filamentous hyphal cells. In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells. There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.
In common with some plant and animal species, more than one hundred fungal species display bioluminescence.
Unique features:
Some species grow as unicellular yeasts that reproduce by budding or fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.
The fungal cell wall is made of a chitin-glucan complex; while glucans are also found in plants and chitin in the exoskeleton of arthropods, fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.
A whitish fan or funnel-shaped mushroom growing at the base of a tree.
Omphalotus nidiformis, a bioluminescent mushroom
Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs, which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks. Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure that fungi and animals do not have. Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants. Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.
Diversity
Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Some can survive the intense UV and cosmic radiation encountered during space travel. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans, parasites that have been responsible for a worldwide decline in amphibian populations. These organisms spend part of their life cycle as a motile zoospore, enabling them to propel itself through water and enter their amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.
As of 2020, around 148,000 species of fungi have been described by taxonomists, but the global biodiversity of the fungus kingdom is not fully understood. A 2017 estimate suggests there may be between 2.2 and 3.8 million species The number of new fungi species discovered yearly has increased from 1,000 to 1,500 per year about 10 years ago, to about 2000 with a peak of more than 2,500 species in 2016. In the year 2019, 1882 new species of fungi were described, and it was estimated that more than 90% of fungi remain unknown The following year, 2905 new species were described—the highest annual record of new fungus names. In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy. Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.
Mycology
Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.
The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus). Ancient peoples have used fungi as food sources—often unknowingly—for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.
History
Mycology became a systematic science after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera. Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated. Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christiaan Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. In the 20th and 21st centuries, advances in biochemistry, genetics, molecular biology, biotechnology, DNA sequencing and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.
Morphology
Microscopic structures
Monochrome micrograph showing Penicillium hyphae as long, transparent, tube-like structures a few micrometres across. Conidiophores branch out laterally from the hyphae, terminating in bundles of phialides on which spherical condidiophores are arranged like beads on a string. Septa are faintly visible as dark lines crossing the hyphae.
An environmental isolate of Penicillium
Hypha
Conidiophore
Phialide
Conidia
Septa
Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 µm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastomosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized. Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota. Coenocytic hyphae are in essence multinucleate supercells.
Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla,[63] and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.
Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella. Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.
Macroscopic structures
Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups. Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.
The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells. The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.
Growth and physiology
Time-lapse photography sequence of a peach becoming progressively discolored and disfigured
Mold growth covering a decaying peach. The frames were taken approximately 12 hours apart over a period of six days.
The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues.[71] The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi).[71] The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.
The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol. Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients. The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha. Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi, or growth by volume expansion during the development of mushroom stipes and other large organs. Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.
Fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known. This process might bear similarity to CO2 fixation via visible light, but instead uses ionizing radiation as a source of energy.
Reproduction
Two thickly stemmed brownish mushrooms with scales on the upper surface, growing out of a tree trunk
Polyporus squamosus
Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph (sexual reproduction) and the anamorph (asexual reproduction). Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.
Asexual reproduction
Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction. The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle. Deuteromycota (alternatively known as Deuteromycetes, conidial fungi, or mitosporic fungi) is not an accepted taxonomic clade and is now taken to mean simply fungi that lack a known sexual stage.
Sexual reproduction
See also: Mating in fungi and Sexual selection in fungi
Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies. Mating experiments between fungal isolates may identify species on the basis of biological species concepts. The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Fungi employ two mating systems: heterothallic species allow mating only between individuals of the opposite mating type, whereas homothallic species can mate, and sexually reproduce, with any other individual or itself.
Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).
In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook (crozier) at the hyphal septum. During cell division, the formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.
Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment. A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis. The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).
In fungi formerly classified as Zygomycota, haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.
Spore dispersal
The spores of most of the researched species of fungi are transported by wind. Such species often produce dry or hydrophobic spores that do not absorb water and are readily scattered by raindrops, for example. In other species, both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances.
Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection. For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g; the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below. Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The hydnoid fungi (tooth fungi) produce spores on pendant, tooth-like or spine-like projections. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies. Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.
Homothallism
In homothallic sexual reproduction, two haploid nuclei derived from the same individual fuse to form a zygote that can then undergo meiosis. Homothallic fungi include species with an Aspergillus-like asexual stage (anamorphs) occurring in numerous different genera, several species of the ascomycete genus Cochliobolus, and the ascomycete Pneumocystis jirovecii. The earliest mode of sexual reproduction among eukaryotes was likely homothallism, that is, self-fertile unisexual reproduction.
Other sexual processes
Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells. The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization and is likely required for hybridization between species, which has been associated with major events in fungal evolution.
Evolution
In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.
The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. The oldest fossilizied mycelium to be identified from its molecular composition is between 715 and 810 million years old. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.
In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).
Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.
Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess, the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary.
Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like "a massive compost heap".
Taxonomy
Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.
There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).
The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances.
The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. As of 2019, nine major lineages have been identified: Opisthosporidia, Chytridiomycota, Neocallimastigomycota, Blastocladiomycota, Zoopagomycotina, Mucoromycota, Glomeromycota, Ascomycota and Basidiomycota.
Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species). Previously considered to be "primitive" protozoa, they are now thought to be either a basal branch of the Fungi, or a sister group–each other's closest evolutionary relative.
The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.
The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.
The Neocallimastigomycota were earlier placed in the phylum Chytridiomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites). They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.
Microscopic view of a layer of translucent grayish cells, some containing small dark-color spheres
Arbuscular mycorrhiza seen under microscope. Flax root cortical cells containing paired arbuscules.
Cross-section of a cup-shaped structure showing locations of developing meiotic asci (upper edge of cup, left side, arrows pointing to two gray cells containing four and two small circles), sterile hyphae (upper edge of cup, right side, arrows pointing to white cells with a single small circle in them), and mature asci (upper edge of cup, pointing to two gray cells with eight small circles in them)
Diagram of an apothecium (the typical cup-like reproductive structure of Ascomycetes) showing sterile tissues as well as developing and mature asci.
Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually. The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago. Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota. Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina. Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.
The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).
Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans.
Fungus-like organisms
Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to an ambiregnal, duplicated taxonomy.
Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and take in nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.
The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.
The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi. Alternatively, Rozella can be classified as a basal fungal group.
The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom. Many Actinomycetales (Actinomycetota), a group with many filamentous bacteria, were also long believed to be fungi.
Ecology
Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.
Symbiosis
Many fungi have important symbiotic relationships with organisms from most if not all kingdoms. These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.
With plants
Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.
A microscopic view of blue-stained cells, some with dark wavy lines in them
The dark filaments are hyphae of the endophytic fungus Epichloë coenophiala in the intercellular spaces of tall fescue leaf sheath tissue
The mycorrhizal symbiosis is ancient, dating back to at least 400 million years. It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients. The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks". A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont. Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes. Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.
With algae and cyanobacteria
A green, leaf-like structure attached to a tree, with a pattern of ridges and depression on the bottom surface
The lichen Lobaria pulmonaria, a symbiosis of fungal, algal, and cyanobacterial species
Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes. Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession, and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions. They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves. As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 27% of known fungi—more than 19,400 species—are lichenized. Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.
With insects
Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Chaetothyriales for several purposes: as a food source, as a structural component of their nests, and as a part of an ant/plant symbiosis in the domatia (tiny chambers in plants that house arthropods). Ambrosia beetles cultivate various species of fungi in the bark of trees that they infest. Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae. At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests. Termites on the African savannah are also known to cultivate fungi, and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts. Fungi growing in dead wood are essential for xylophagous insects (e.g. woodboring beetles). They deliver nutrients needed by xylophages to nutritionally scarce dead wood. Thanks to this nutritional enrichment the larvae of the woodboring insect is able to grow and develop to adulthood. The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.
A thin brown stick positioned horizontally with roughly two dozen clustered orange-red leaves originating from a single point in the middle of the stick. These orange leaves are three to four times larger than the few other green leaves growing out of the stick, and are covered on the lower leaf surface with hundreds of tiny bumps. The background shows the green leaves and branches of neighboring shrubs.
The plant pathogen Puccinia magellanicum (calafate rust) causes the defect known as witch's broom, seen here on a barberry shrub in Chile.
Gram stain of Candida albicans from a vaginal swab from a woman with candidiasis, showing hyphae, and chlamydospores, which are 2–4 µm in diameter.
Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae, tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease, Cryphonectria parasitica responsible for chestnut blight, and Phymatotrichopsis omnivora causing Texas Root Rot, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets. Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed). This same principle is applied to fungi-feeding parasites, including Asterotremella albida, which feeds on the fruit bodies of other fungi both while they are living and after they are dead.
Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma, and Pneumocystis. Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.
As targets of mycoparasites
Organisms that parasitize fungi are known as mycoparasitic organisms. About 300 species of fungi and fungus-like organisms, belonging to 13 classes and 113 genera, are used as biocontrol agents against plant fungal diseases. Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms. Fungi can also become the target of infection by mycoviruses.
Communication
Main article: Mycorrhizal networks
There appears to be electrical communication between fungi in word-like components according to spiking characteristics.
Possible impact on climate
According to a study published in the academic journal Current Biology, fungi can soak from the atmosphere around 36% of global fossil fuel greenhouse gas emissions.
Mycotoxins
(6aR,9R)-N-((2R,5S,10aS,10bS)-5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-2H-oxazolo[3,2-a] pyrrolo[2,1-c]pyrazin-2-yl)-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg] quinoline-9-carboxamide
Ergotamine, a major mycotoxin produced by Claviceps species, which if ingested can cause gangrene, convulsions, and hallucinations
Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea. Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.
Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi. Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory). Many fungal secondary metabolites (or derivatives) are used medically, as described under Human use below.
Pathogenic mechanisms
Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen's virulence. Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis. The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.
Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages. Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response. Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.
Human use
See also: Human interactions with fungi
Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres
Saccharomyces cerevisiae cells shown with DIC microscopy
The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. Methods have been developed for genetic engineering of fungi, enabling metabolic engineering of fungal species. For example, genetic modification of yeast species—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms. Fungi-based industries are sometimes considered to be a major part of a growing bioeconomy, with applications under research and development including use for textiles, meat substitution and general fungal biotechnology.
Therapeutic uses
Modern chemotherapeutics
Many species produce metabolites that are major sources of pharmacologically active drugs.
Antibiotics
Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties. Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria. Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.
Other
Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections, and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom. Psilocybin from fungi is investigated for therapeutic use and appears to cause global increases in brain network integration. Fungi produce compounds that inhibit viruses and cancer cells. Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan. In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.
Traditional medicine
Upper surface view of a kidney-shaped fungus, brownish-red with a lighter yellow-brown margin, and a somewhat varnished or shiny appearance
Two dried yellow-orange caterpillars, one with a curly grayish fungus growing out of one of its ends. The grayish fungus is roughly equal to or slightly greater in length than the caterpillar, and tapers in thickness to a narrow end.
The fungi Ganoderma lucidum (left) and Ophiocordyceps sinensis (right) are used in traditional medicine practices
Certain mushrooms are used as supposed therapeutics in folk medicine practices, such as traditional Chinese medicine. Mushrooms with a history of such use include Agaricus subrufescens, Ganoderma lucidum, and Ophiocordyceps sinensis.
Cultured foods
Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings. Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation. Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso while Rhizopus species are used for making tempeh. Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli. Quorn, a meat substitute, is made from Fusarium venenatum.
My entry for Pam's "Faces in inanimate objects" theme. I think there's a smiley face in there, and the ketone strip is a bit like a tongue.
We bought this monitor to measure the amount of ketones in our blood to make sure we're in ketosis. Ketosis is a metabolic state in which the liver produces small organic molecules called ketone bodies at “sufficient” levels. This is upwards of 0.5mmol so I'm only just there this morning. When your body is creating enough ketone bodies it's not using glycogen as it's primary fuel source, instead it's using ketone bodies. This has some real advantages over glycogen because they are made from fat which we all have lots of (even really skinny people) so we never run out, and it makes it very easy to reduce or maintain your body fat. There are some endurance ahletes doing amazing things in ketosis like record breaking 100 mile runs with barely any food. It sounded too good to be true so I had to give it a go.
To get your body to run on ketone bodies you need to completely eliminate carbohydrate from your diet, absolutely no sugar, potatoes, apples, all that stuff. You also have to make sure you don't eat too much protein either which is tricky when you're cutting out all the carbs. It means you have to eat a lot of fat which we're all mentally conditioned to avoid. I'm leaving the fat on my bacon now and I even ate a whole spoonful of coconut oil by itself the other day. It's very odd.
Over the last 3 months I've consumed no carbohydrate and loads of fat and lost 11.4kg, or 1st 11lb, and gone from 24% to 16% body fat. I've been taking measurements and I'm pretty certain I've not lost any muscle. Everytime I look in the mirror I laugh at how much my body has changed, it's unreal. Quite a few people have told me to "be careful" but I'm not sure they understand what's happening and how my body is not in a state of stress, I'm not starving myself like you would with a calorie restricted low fat diet. I feel great, loads better than when I was eating carbs. I'm riding my bike 10 hours a week, doing pilates and free weights and I have constant energy from when I wake to when I go to bed and I'm not hungry all day like when I ate carbs.
Peter Attia explains it all in detail but it's a bit heavy going:
eatingacademy.com/nutrition/ketosis-advantaged-or-misunde...
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Declawing of crabs
Cooked Alaskan king crab claws
Declawing of crabs is the process whereby one or both claws of a live crab (including king crabs) are manually pulled off and the animal is then returned to the water. It occurs in several fisheries worldwide, such as in the Florida stone crab (Menippe mercenaria) fishery, the north-east Atlantic deep-water red crab (Chaceon affinis) fishery and in southern Iberia, where the major claws of the fiddler crab Uca tangeri are harvested. Around Northern Europe, an extensive fishery exists for claws of the edible crab, Cancer pagurus. The practice is defended because some crabs can naturally autotomise (shed) limbs and then about a year later after a series of moults, regenerate these limbs.[1] It is argued that declawing therefore provides a sustainable fishery. Claw removal is also promoted to assist in handling of animals, and to decrease losses through entanglement in nets and cannibalism.[2][3] Declawing crabs is legal in the UK since revocation in 2000 of the Crab Claws (Prohibition of Landing) Order 1986. One crab that is subject to widespread declawing is the Florida stone crab, for which tourist information is provided.[4]
Contents
ProcedureEdit
General anatomy of a fiddler crab
To perform declawing, the claws are snapped downward away from the crab. To ensure a clean break along the natural fracture plane, one finger is placed on the basal cheliped joint. With the cheliped fully extended, a quick, firm downward motion normally removes the claw cleanly. The break usually occurs at the basi-ischum between the coxa at the base of the leg and the merus.
ProductionEdit
In the 1976–77 trapping season, about 50,000 kg of claws were harvested in the Everglades National Park.[5] This was probably less than 5% of the total Floridian harvest, which has averaged more than 1,000,000 kilograms since 1974.[6]
In Florida during the 1995–96 to 2004–05 fishing seasons, fishers declawed approximately 10.5 million crabs during each 7-month fishing season. The weight of crab claws landings varied without trend since 1989–90. Peak landings were 1.6 million kg statewide in the 1997–98 fishing season. Statewide landings for 2004–05 were 1.4 million kg of claws.[7]
Effects on mortalityEdit
Florida stone crab claws served as food
Under experimental conditions, but using commercially accepted techniques, 47% of Florida stone crabs that had both claws removed died after declawing, and 28% of single claw amputees died; 76% of the casualties died within 24 hours of declawing. The claws constituted 51% of the total weight of the crabs before declawing.[8] In the wild, where declawed crabs must compete for food, mates, and shelter, and avoid predators, the mortality rate is likely to be higher. Declawed crabs survive by switching from predation to scavenging.[9] The occurrence of regenerated claws in the fishery harvest is low, with studies calculating from less than 10% (1978),[8] 13% (2006),[7] to 20% (2010).[10] Larger, older crabs generally do not survive long enough to regrow their claws, as they are near the end of their lifespan.
Effects on feedingEdit
Most crabs use their claws for capturing and eating prey. A crab with one claw removed would therefore be disadvantaged in subsequent feeding and a crab with both claws removed even more so. In a study on the effects of declawing on feeding, autotomy induced (declawed) crabs consumed significantly fewer mussels and less mussel mass, but ate more mass of fish (a more readily handled food source). This indicates that the effect of autotomy was a reduction of the ability to feed on mussels, rather than a general reduction of feeding motivation.[2] In a second study, there was no discernible difference in the amount of food consumed by crabs surviving declawing and control crabs.[8] It has been argued that should a crab survive declawing it will not be able to feed effectively and may subsequently die of starvation.[3]
Effects on activityEdit
Declawed crabs show significantly lower activity levels than negative controls.[8]
Pain and stress caused by declawingEdit
There is debate about whether invertebrates can experience pain. Some of the most compelling evidence for pain in invertebrates exists for crustaceans in terms of trade-offs between stimulus avoidance and other motivational requirements. Evidence of the ability for crabs to feel pain is supported by their possessing an opioid receptor system, showing learned avoidance to putatively painful stimuli, and responding appropriately to analagesics and anaesthetics. These all indicate it is likely that crabs can experience pain during declawing.
It has been argued that because crabs can autotomise (self-amputate) their claws, manual declawing along these natural fracture planes will not cause pain. However, a lack or reduction of pain during autotomy remains to be verified. Moreover, declawing results in a physiological stress response in the edible crab, as indicated by increases in haemolymph glucose and lactate and a decrease in glycogen. This stress is evident both in the short term (< 10 min) and the long term (24 h). Further, declawing is more stressful, results in bigger wounds and causes significant mortality compared to induced autotomy.[11]
See alsoEdit
Crab fisheries
Crustacean
Pain in animals
Pain in crustaceans
Pain in invertebrates
ReferencesEdit
^ "Stone crabs FAQs". Florida Fish and Wildlife Conservation Commission. Retrieved 23 September 2012.
^ a b Lynsey Patterson; Jaimie T. A. Dick; Robert W. Elwood (2009). "Claw removal and feeding ability in the edible crab, Cancer pagurus: implications for fishery practice". Applied Animal Behaviour Science. 116 (2): 302–305. doi:10.1016/j.applanim.2008.08.007.
^ a b Queen's University, Belfast (10 October 2007). "Declawing crabs may lead to their death". Science Daily. Retrieved 21 September 2012.
^ "Recreational stone crabbing information". Florida Fish and Wildlife Conservation Commission. Retrieved November 4, 2012.
^ G. E. Davis; E. B. Thue (1977). Annual fishery management report for Everglades National Park, Florida, No. 1. Homestead, Florida: Everglades National Park, U. S. National Park Service.
^ Florida Department of Natural Resources (1977). Florida landings, annual summary, 1975. Current Fisheries Statistics. 6919. Washington, DC: NOAA/National Marine Fisheries Service.
^ a b "The 2006 Stock Assessment Update for the Stone Crab, Menippe spp., Fishery in Florida". Florida Fish and Wildlife Conservation Commission. Retrieved 23 September 2012.
^ a b c d Gary E. Davis; Douglas S. Baughman; James D. Chapman; Donald MacArthur; Alan C. Pierce (1978). Mortality associated with declawing stone crabs, Menippe mercenaria (PDF). US National Park Service. Report T-522.
^ Stone Crab FAQ: If a stone crab looses [sic] both claws how can it eat and defend itself?
^ Species Account - Invertebrates: Florida Stone Crab (Menippe mercenaria) and Gulf Stone Crab (M. adina)
^ Lynsey Patterson; Jaimie T. A. Dick; Robert W. Elwood (2007). "Physiological stress responses in the edible crab, Cancer pagurus, to the fishery practice of de-clawing". Marine Biology. 152 (2): 265–272. doi:10.1007/s00227-007-0681-5.
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Effective growth of the muscle mass
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Fast absorbing amino acids
Stores glycogen much faster
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Individuals are additional really conscious of wellness and desire to start eating in a healthier approach. But, diet nevertheless stays, partly, a secret. What’s wonderful is the fact that this short article offers you a lots of helpful suggestions that may provide you the best way to start your trip towards a healthy and diet packed existence. There are numerous advantages to eating garlic, aside from worrying off skeletons! Evaluation demonstrates that garlic aids your cholesterol, blood pressure and triglycerides. Each time your metabolism large your own body may normally burn up fat on itself that will be one key of the machine. You will burn a great deal quicker when you enhance your metabolism is large. The 5 days’ interval includes cheat days, meats exhaustion, move day, typical carbohydrate days, along with fats day. The be untrue evening may be the location it is possible to each food that you simply would rather for instance pizzas or ice cream. You may uncover it unusual nevertheless really It Is an area of the way to enhance your metabolism and fat loss hormones.
This vitamin is likely to be present in red beef and particular types of seafood much like salmons. Omega-three essential fatty acids are extremely essential for any bodybuilder. This vitamin assists the muscles to become additional insulin delicate thus they enhance glycogen to become saved within the muscles and likewise proteins merely enter the muscles. The maintenance of glutamine stores could be increased by these omega-three essential fatty acids. Dane Fletcher may be the globe-big expert on training, diet, and products. Merely as you do not wait until you are dehydrated sooner than you renew fluids or calories, you never have to attend until you’re cramping before replacing electrolytes. The aim in replacing electrolytes would be to preserve specific physical functions at maximum levels. The system includes an extravagant strategy of tracking and sustaining proper chemical levels. Because man or woman work-reduction differs significantly throughout workout and while about the program, the individual system doesn’t and cannot effectively substitute what it expends (chemicals lost cannot be transformed by chemicals consumed) till after your round. A mixed solution handles the capabilities of quite a bit of nutrients and stops the undesirable effects of nutrient deficiencies. For example, a deficit in calcium may lead to achy bones, cardiovascular palpitations, anxiety and hypertension. A deficit in potassium may reveal itself in physical exhaustion, reduced response execute, muscle pains, and variations in pulse, problems and enema.
Quick foods will not be the whole meals. It may not exchange the nutrients provided by a healthy diet of whole foods vitamins. Healthy diet is undoubtedly among the easiest methods to preserve a sound body. Great food diet with proper vitamins can-as a great complement for healthy body. You can scarcely disregard the benefits of wellness and diet that it’ll perhaps perform in keeping your health. Greater wellness indicates greater returning to great healthy meals within their normal condition.
Just Like A person
ready your meals
long haul it’s cheaper to sort out at home
Phrases of information
Day Chemical Diet
Calories Diet Menu
make sure that to Consume Adequate Protein
This might help revitalize your tired experience and aid fireplace up the ideas. America has come to be an overweight country, and occasionally situations it is attributed on our passion with junk food. Quick foods are extremely harmful, along with a every single day consumption of these meals can offer extreme levels of fatty foods and calories. Attempt to keep up with the consumption of quick food reduced and make an effort to pack a lunchtime in the place of speeding down towards the indigenous fast-food combined at lunchtime. Great nutrition can help reduce tension in the event that you include dry apricots for your diet. This magnesium-rich fruit is just a real method of relax and deal with evening-today demands.
An 1800-calorie diet regime performs properly when along with gentle practice for big-sized girls or small-sized males who wish to look after their present fat and typical workout for small-sized males who would like to fall lbs. The 3-day cardiac diet was created in the Cleveland Center like a surprisingly low fat diet and quick weightless routine designed to assist cardiac people fall pounds rapidly. And so the name three-day cardiac diet. The very first utilization of the 3-day cardiac diet would be to accomplish quick and brief-period of time weight-reduction in addition to decrease the threat of cardiovascular disease.
Fibber works a purpose within our wellness. Efficiently-acknowledged advantages of soluble fiber range from the avoidance of constipation, piles, and diverticulitis, in addition to weight management. In addition to, dietary fiber might help lower blood cholesterol levels. Using the truly useful everyday fiber consumption at 38 grams for person guys (19-50 years) and 25 grams for girls, it’s de facto useful to become familiar with some extreme fiber meals to ensure you receive enough. In the event you will also be a sports lover and have to observe some changes inside your sport and wellness, follow the info below. Author: Debbie Kiser People that are involved in sporting activities possess a lot unique dietary requirements when compared with peculiar people. The cause of this really is that they’re additional physically energetic and also the need of the system for replenishment is very good. Becoming an athlete, following a appropriate sports diet regime might make a substantial impact inside your effectiveness and general wellness. Beneath are a few of the fundamental vitamins which can be found in meals that should be in what you eat. If you have signs of heart problems or a heart failure you must to consult your nutritionist.
This dinner ought to be in liquid type therefore to awaken, chug it back-very rapidly and just, after which it mind straight back to sleep. This places your system into an anabolism condition and raises your fats using metabolism whilst you’re resting. Author: Akansha the most crucial element which must retain in ideas is top quality and usefulness of the products that impacts one’s development of your body masses. This subsequently leads to a sense of lively energy and well being. Each living patient emits bio photons, and also the more bio photons an organism produces, the larger its vigor and possibility of exchange of vigor towards the one which uses it. Therefore, as a result of this the milder a food may store, the healthier it is. You-can’t uncover these bio photons in packaged foods. Plus, processed food items are laden with harmful additives, artificial hues, and synthetic flavorings.
You’d potentially alter positioning; you’ll have observed oneself just like a defensive person, however the supervisor might help you like a winger, or even a striker. Getting involved in football could keep you match and healthful, so when you’re getting your personal activity significantly, you’d perhaps begin to suppose more about the body, in addition to your daily diet program. Sustained 1-hour half hour on the Saturday is just a difficult job, especially if you’re not used to it, and not inside the greatest shape.? You’ll rapidly boost however, if you should be seriously cantered on your individual sport. Whenever a mom-to-be is experiencing morning nausea, the largest mistake she could make is contemplating when she doesn’t consume, she will experience greater, Krieger stated. The precise reasons for day nausea aren’t recognized, nevertheless it may be brought on by hormonal modifications or lower blood sugar levels, prior to the Mayo Clinic. It might keep on dunes of sickness and vomiting in certain women, especially throughout the main 3 months of pregnancy. And “it is not at all occurring just inside the day,” Krieger explained. It is greater to consume tiny levels of meals that not have a smell, because doors could also upset the belly, she suggested.
For More Info: Celtic Nutrition
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A very thorough approach to diabetes treatment from the point of view of prevention and reversal of diabetes symptoms. Frank Shallenberger is a medical doctor combining his own testing methods called Bio-energy testing with a multi-pronged holistic treatment that includes diet, supplements and exercise. The Bio-energy test , which involves testing your body on a treadmill, evaluates how well you are producing energy and metabolizing fat, as well as your optimum caloric intake and carbohydrate intake. Also adrenal gland function, heart and lung function. Unfortunately I would have to go to his office in Nevada to get this evaluation. It used to be more available, but the economic collapse may have had an impact and the fact that his treatment plan requires patients who are motivated. www.burstingwithenergy.net/bio-energy-testing.php
The book describes his theory that diabetes is an energy production problem on a cellular level and not simply a question of the pancreas not producing enough insulin. He fully admits that his theory has not been proven but his treatment plan still works per his observations of his patients.
He distinguishes two types of Type 2 diabetes. I call them Stage 1 and Stage 2. Stage 1 involves high insulin and insulin resistance. When the pancreas creates so much insulin (produced in the islet cells), the end product is excessive free radicals. Free radicals are produced as a byproduct of all cellular energy production so it is normal until the cell is overtaxed. Then the cell becomes inefficient and produces even more free radicals as a result. In the case of the pancreas this is because of too much carbohydrates demanding high insulin production. And if you are genetically prone to diabetes this is more likely, but you don't have to be this genotype to have it happen to you. So basically everybody is headed for this route due to our high carb food culture.
Stage 2 is when the pancreas does not create enough insulin which is what happens next. This means the islet cells are destroying themselves with free radicals. So you want to catch Type 2 diabetes before it gets to this point in order to reverse it. Otherwise you have to go the insulin injecting route. For this he highly recommends Dr. Bernstein's book.
The problem with conventional medicine, he says, is the use of drugs to make the failing islet cells produce more insulin. This just makes those islet cells burn out faster. Conventional medicine does not go to the root of the problem and ask what causes insulin resistance in the first place and how it can be corrected. And how to protect the pancreas from free-radical damage. This is what his approach is about. It can also be applied to overall health and energy boosting.
His eight pronged approach addresses.
DIET: low carb, above ground vegetables, saturated fats, high protein and a balance of omega 3 and omega 6 fats. He is very high-fat friendly and also believes that the low-fat premise is erroneous.
SUPPLEMENTS: to aid oxygen metabolism, increase fat metabolism and increase insulin sensitivity, increase liver function, increase insulin output, increase adrenal function and improve and increase sleep.
EXERCISE, but not of a prolonged type that keeps your heart rate high. Counsels interval training, anaerobic burst and resistance training. 30-40 minutes a day, six days a week. Interval training of three of the days and resistance training on the other three.
SUPPORTING THE LIVER WITH ANTIOXIDENT NUTRIENTS. These are vitamins C and E, lipoic acid, glutathione (converted from N-acetyl-cysteine , selenium, manganese, copper and zinc.
To check optimum liver functioning look at albumin levels. Albumin, which is a protein in the blood is entirely made by the liver so levels of albumin are indicative of good liver function. Optimal is 4.5 g/dl to 5. Normal range is 3.5 to 5 so a doctor won't care if it's in that range even though less than 4.5 means low energy production.
Glycogen also important to the detoxifying function of the liver. Results from adequate amount of protein. Fiber from vegetables and seeds, not grains, is good for absorbing bile salts which is how the liver gets rid of toxins.
ADEQUATE SLEEP supplemented with 5-HTP and tiny bit of melatonin, not sleep medications which interfere with development of deeper levels of sleep.
STRESS REDUCTION through relaxation exercises and meditation
CORRECTING HORMONE IMBALANCES, not just insulin but thyroid, cortisol, DHEA testosterone and growth hormone imbalances.
Low levels of thyroid results in a decreased production of insulin. Mercury is toxic to the thyroid gland. And possibly fluoride and x-rays. Elevated cholesterol levels, especially LDL are indicative of thyroid hormone deficiency. Thyroid makes 7% of T3 hormone and 93% of T4 hormones. The liver converts T4 to T3. T3 vital for energy production.
Cortisol can best be measured with a saliva test.
DHEA affects insulin resistance.
Growth hormone stimulates muscle and bone cells. A deficiency contributes to loss of muscle mass which in turn aggravates insulin resistance. Growth hormone replenishment is helped by exercise, sleep and fasting. Tested with a blood test for IGF-1
OXIDATIVE MEDICINE for those too impaired to exercise.
Had to get this book through inter-library loan, but it is cheap to buy used. I just wanted to make sure it was worth having.
A fungus (pl.: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the traditional eukaryotic kingdoms, along with Animalia, Plantae and either Protista or Protozoa and Chromista.
A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (i.e. they form a monophyletic group), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology (from the Greek μύκης mykes, mushroom). In the past mycology was regarded as a branch of botany, although it is now known that fungi are genetically more closely related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and also parasites. They may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment. They have long been used as a direct source of human food, in the form of mushrooms and truffles; as a leavening agent for bread; and in the fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological pesticides to control weeds, plant diseases, and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals, including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g., rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.
The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of the fungus kingdom, which has been estimated at 2.2 million to 3.8 million species. Of these, only about 148,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christiaan Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the first decade of the 21st century have helped reshape the classification within the fungi kingdom, which is divided into one subkingdom, seven phyla, and ten subphyla.
Etymology
The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos (σφόγγος 'sponge'), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm ('sponge') and Schimmel ('mold').
The word mycology is derived from the Greek mykes (μύκης 'mushroom') and logos (λόγος 'discourse'). It denotes the scientific study of fungi. The Latin adjectival form of "mycology" (mycologicæ) appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon. The word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. also refers to mycology as the study of fungi.
A group of all the fungi present in a particular region is known as mycobiota (plural noun, no singular). The term mycota is often used for this purpose, but many authors use it as a synonym of Fungi. The word funga has been proposed as a less ambiguous term morphologically similar to fauna and flora. The Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN) in August 2021 asked that the phrase fauna and flora be replaced by fauna, flora, and funga.
Characteristics
Fungal hyphae cells
Hyphal wall
Septum
Mitochondrion
Vacuole
Ergosterol crystal
Ribosome
Nucleus
Endoplasmic reticulum
Lipid body
Plasma membrane
Spitzenkörper
Golgi apparatus
Fungal cell cycle showing Dikaryons typical of Higher Fungi
Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Although inaccurate, the common misconception that fungi are plants persists among the general public due to their historical classification, as well as several similarities. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era). Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:
With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type. They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals).
With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.
With plants: Fungi have a cell wall and vacuoles. They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.
With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.
The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper. Both fungi and oomycetes grow as filamentous hyphal cells. In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells. There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.
In common with some plant and animal species, more than one hundred fungal species display bioluminescence.
Unique features:
Some species grow as unicellular yeasts that reproduce by budding or fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.
The fungal cell wall is made of a chitin-glucan complex; while glucans are also found in plants and chitin in the exoskeleton of arthropods, fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.
A whitish fan or funnel-shaped mushroom growing at the base of a tree.
Omphalotus nidiformis, a bioluminescent mushroom
Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs, which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks. Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure that fungi and animals do not have. Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants. Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.
Diversity
Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Some can survive the intense UV and cosmic radiation encountered during space travel. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans, parasites that have been responsible for a worldwide decline in amphibian populations. These organisms spend part of their life cycle as a motile zoospore, enabling them to propel itself through water and enter their amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.
As of 2020, around 148,000 species of fungi have been described by taxonomists, but the global biodiversity of the fungus kingdom is not fully understood. A 2017 estimate suggests there may be between 2.2 and 3.8 million species The number of new fungi species discovered yearly has increased from 1,000 to 1,500 per year about 10 years ago, to about 2000 with a peak of more than 2,500 species in 2016. In the year 2019, 1882 new species of fungi were described, and it was estimated that more than 90% of fungi remain unknown The following year, 2905 new species were described—the highest annual record of new fungus names. In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy. Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.
Mycology
Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.
The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus). Ancient peoples have used fungi as food sources—often unknowingly—for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.
History
Mycology became a systematic science after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera. Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated. Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christiaan Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. In the 20th and 21st centuries, advances in biochemistry, genetics, molecular biology, biotechnology, DNA sequencing and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.
Morphology
Microscopic structures
Monochrome micrograph showing Penicillium hyphae as long, transparent, tube-like structures a few micrometres across. Conidiophores branch out laterally from the hyphae, terminating in bundles of phialides on which spherical condidiophores are arranged like beads on a string. Septa are faintly visible as dark lines crossing the hyphae.
An environmental isolate of Penicillium
Hypha
Conidiophore
Phialide
Conidia
Septa
Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 µm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastomosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized. Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota. Coenocytic hyphae are in essence multinucleate supercells.
Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla,[63] and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.
Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella. Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.
Macroscopic structures
Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups. Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.
The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells. The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.
Growth and physiology
Time-lapse photography sequence of a peach becoming progressively discolored and disfigured
Mold growth covering a decaying peach. The frames were taken approximately 12 hours apart over a period of six days.
The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues.[71] The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi).[71] The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.
The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol. Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients. The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha. Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi, or growth by volume expansion during the development of mushroom stipes and other large organs. Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.
Fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known. This process might bear similarity to CO2 fixation via visible light, but instead uses ionizing radiation as a source of energy.
Reproduction
Two thickly stemmed brownish mushrooms with scales on the upper surface, growing out of a tree trunk
Polyporus squamosus
Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph (sexual reproduction) and the anamorph (asexual reproduction). Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.
Asexual reproduction
Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction. The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle. Deuteromycota (alternatively known as Deuteromycetes, conidial fungi, or mitosporic fungi) is not an accepted taxonomic clade and is now taken to mean simply fungi that lack a known sexual stage.
Sexual reproduction
See also: Mating in fungi and Sexual selection in fungi
Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies. Mating experiments between fungal isolates may identify species on the basis of biological species concepts. The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Fungi employ two mating systems: heterothallic species allow mating only between individuals of the opposite mating type, whereas homothallic species can mate, and sexually reproduce, with any other individual or itself.
Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).
In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook (crozier) at the hyphal septum. During cell division, the formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.
Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment. A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis. The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).
In fungi formerly classified as Zygomycota, haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.
Spore dispersal
The spores of most of the researched species of fungi are transported by wind. Such species often produce dry or hydrophobic spores that do not absorb water and are readily scattered by raindrops, for example. In other species, both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances.
Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection. For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g; the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below. Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The hydnoid fungi (tooth fungi) produce spores on pendant, tooth-like or spine-like projections. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies. Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.
Homothallism
In homothallic sexual reproduction, two haploid nuclei derived from the same individual fuse to form a zygote that can then undergo meiosis. Homothallic fungi include species with an Aspergillus-like asexual stage (anamorphs) occurring in numerous different genera, several species of the ascomycete genus Cochliobolus, and the ascomycete Pneumocystis jirovecii. The earliest mode of sexual reproduction among eukaryotes was likely homothallism, that is, self-fertile unisexual reproduction.
Other sexual processes
Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells. The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization and is likely required for hybridization between species, which has been associated with major events in fungal evolution.
Evolution
In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.
The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. The oldest fossilizied mycelium to be identified from its molecular composition is between 715 and 810 million years old. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.
In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).
Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.
Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess, the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary.
Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like "a massive compost heap".
Taxonomy
Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.
There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).
The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances.
The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. As of 2019, nine major lineages have been identified: Opisthosporidia, Chytridiomycota, Neocallimastigomycota, Blastocladiomycota, Zoopagomycotina, Mucoromycota, Glomeromycota, Ascomycota and Basidiomycota.
Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species). Previously considered to be "primitive" protozoa, they are now thought to be either a basal branch of the Fungi, or a sister group–each other's closest evolutionary relative.
The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.
The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.
The Neocallimastigomycota were earlier placed in the phylum Chytridiomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites). They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.
Microscopic view of a layer of translucent grayish cells, some containing small dark-color spheres
Arbuscular mycorrhiza seen under microscope. Flax root cortical cells containing paired arbuscules.
Cross-section of a cup-shaped structure showing locations of developing meiotic asci (upper edge of cup, left side, arrows pointing to two gray cells containing four and two small circles), sterile hyphae (upper edge of cup, right side, arrows pointing to white cells with a single small circle in them), and mature asci (upper edge of cup, pointing to two gray cells with eight small circles in them)
Diagram of an apothecium (the typical cup-like reproductive structure of Ascomycetes) showing sterile tissues as well as developing and mature asci.
Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually. The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago. Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota. Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina. Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.
The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).
Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans.
Fungus-like organisms
Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to an ambiregnal, duplicated taxonomy.
Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and take in nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.
The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.
The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi. Alternatively, Rozella can be classified as a basal fungal group.
The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom. Many Actinomycetales (Actinomycetota), a group with many filamentous bacteria, were also long believed to be fungi.
Ecology
Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.
Symbiosis
Many fungi have important symbiotic relationships with organisms from most if not all kingdoms. These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.
With plants
Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.
A microscopic view of blue-stained cells, some with dark wavy lines in them
The dark filaments are hyphae of the endophytic fungus Epichloë coenophiala in the intercellular spaces of tall fescue leaf sheath tissue
The mycorrhizal symbiosis is ancient, dating back to at least 400 million years. It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients. The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks". A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont. Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes. Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.
With algae and cyanobacteria
A green, leaf-like structure attached to a tree, with a pattern of ridges and depression on the bottom surface
The lichen Lobaria pulmonaria, a symbiosis of fungal, algal, and cyanobacterial species
Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes. Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession, and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions. They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves. As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 27% of known fungi—more than 19,400 species—are lichenized. Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.
With insects
Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Chaetothyriales for several purposes: as a food source, as a structural component of their nests, and as a part of an ant/plant symbiosis in the domatia (tiny chambers in plants that house arthropods). Ambrosia beetles cultivate various species of fungi in the bark of trees that they infest. Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae. At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests. Termites on the African savannah are also known to cultivate fungi, and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts. Fungi growing in dead wood are essential for xylophagous insects (e.g. woodboring beetles). They deliver nutrients needed by xylophages to nutritionally scarce dead wood. Thanks to this nutritional enrichment the larvae of the woodboring insect is able to grow and develop to adulthood. The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.
A thin brown stick positioned horizontally with roughly two dozen clustered orange-red leaves originating from a single point in the middle of the stick. These orange leaves are three to four times larger than the few other green leaves growing out of the stick, and are covered on the lower leaf surface with hundreds of tiny bumps. The background shows the green leaves and branches of neighboring shrubs.
The plant pathogen Puccinia magellanicum (calafate rust) causes the defect known as witch's broom, seen here on a barberry shrub in Chile.
Gram stain of Candida albicans from a vaginal swab from a woman with candidiasis, showing hyphae, and chlamydospores, which are 2–4 µm in diameter.
Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae, tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease, Cryphonectria parasitica responsible for chestnut blight, and Phymatotrichopsis omnivora causing Texas Root Rot, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets. Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed). This same principle is applied to fungi-feeding parasites, including Asterotremella albida, which feeds on the fruit bodies of other fungi both while they are living and after they are dead.
Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma, and Pneumocystis. Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.
As targets of mycoparasites
Organisms that parasitize fungi are known as mycoparasitic organisms. About 300 species of fungi and fungus-like organisms, belonging to 13 classes and 113 genera, are used as biocontrol agents against plant fungal diseases. Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms. Fungi can also become the target of infection by mycoviruses.
Communication
Main article: Mycorrhizal networks
There appears to be electrical communication between fungi in word-like components according to spiking characteristics.
Possible impact on climate
According to a study published in the academic journal Current Biology, fungi can soak from the atmosphere around 36% of global fossil fuel greenhouse gas emissions.
Mycotoxins
(6aR,9R)-N-((2R,5S,10aS,10bS)-5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-2H-oxazolo[3,2-a] pyrrolo[2,1-c]pyrazin-2-yl)-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg] quinoline-9-carboxamide
Ergotamine, a major mycotoxin produced by Claviceps species, which if ingested can cause gangrene, convulsions, and hallucinations
Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea. Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.
Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi. Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory). Many fungal secondary metabolites (or derivatives) are used medically, as described under Human use below.
Pathogenic mechanisms
Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen's virulence. Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis. The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.
Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages. Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response. Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.
Human use
See also: Human interactions with fungi
Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres
Saccharomyces cerevisiae cells shown with DIC microscopy
The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. Methods have been developed for genetic engineering of fungi, enabling metabolic engineering of fungal species. For example, genetic modification of yeast species—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms. Fungi-based industries are sometimes considered to be a major part of a growing bioeconomy, with applications under research and development including use for textiles, meat substitution and general fungal biotechnology.
Therapeutic uses
Modern chemotherapeutics
Many species produce metabolites that are major sources of pharmacologically active drugs.
Antibiotics
Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties. Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria. Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.
Other
Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections, and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom. Psilocybin from fungi is investigated for therapeutic use and appears to cause global increases in brain network integration. Fungi produce compounds that inhibit viruses and cancer cells. Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan. In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.
Traditional medicine
Upper surface view of a kidney-shaped fungus, brownish-red with a lighter yellow-brown margin, and a somewhat varnished or shiny appearance
Two dried yellow-orange caterpillars, one with a curly grayish fungus growing out of one of its ends. The grayish fungus is roughly equal to or slightly greater in length than the caterpillar, and tapers in thickness to a narrow end.
The fungi Ganoderma lucidum (left) and Ophiocordyceps sinensis (right) are used in traditional medicine practices
Certain mushrooms are used as supposed therapeutics in folk medicine practices, such as traditional Chinese medicine. Mushrooms with a history of such use include Agaricus subrufescens, Ganoderma lucidum, and Ophiocordyceps sinensis.
Cultured foods
Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings. Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation. Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso while Rhizopus species are used for making tempeh. Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli. Quorn, a meat substitute, is made from Fusarium venenatum.
Scientific Name: Scarabum electrodea
Family: Scarab Beetle
Olimar's Notes:
This specimen is representative of an insect hybrid that uses electricity in addition to glycogen for its energy. Although difficult to confirm due to their microscopic size, tiny hairs on the creature's legs cause the friction that generates the electrical charge. The electrical charge is processed by the creature's internal machina battery structure, and then stored as a deus electrifical field. As this field reaches critical levels, surplus electricity is emitted, resulting in a low voltage current that is transmitted between specimens. It can shock other creatures in the immediate vicinity. Considering this process, it can be surmised that the largest impetus to pack behavior is not so much for synergic effect of producing as a pack as it is to take advantage of this most effective means of group preseveration.
Louie's Notes:
Drain the electrical charge before boiling. Although it is possible to eat an anode beetle while it is charged, doing so may result in an unpleasant tingling sensation.
For more photos and details about this creation, click here!
Photo and Creation © 2009 Filip Johannes Felberg
Olimar and Louie's Notes © Nintendo
Creatine can rebuild APT. This is technically called triphosphate and it is a chemical in the body that powers your muscles. When you are lifting, ATP will help your muscles contract. With each contraction the amount of ATP in your system will decrease until you are full of it to the point where you cannot longer lift. The only way to replenish ATP in your muscles is with creatine.
Creatine will increase your ability to store glycogen. Your muscles use glycogen to fuel the anabolic process. You need to have an adequate amount of glycogen to help your muscles recover after an intense workout. By doing this, your muscles will grow bigger and faster as well.
The concept of metabolic Syndrome was first introduced as Syndrome X by Gerald Reaven He delivered the Banting Lecture in 1988 at the American Diabetes Association national meeting. He stated that Syndrome X is aggregation of independent, risk factors present in the same individual which are seen in coronary heart disease (CHD). The various risk factors included in the syndrome were insulin resistance, defined as the inability of insulin to optimally stimulate the transport of glucose into the body’s cell (hyperinsulinemia or impared glucose tolerance, hypertension, hypertriglyceridemia, and low, high-density lipotrotein cholesterol (HDL) [1]. Syndrome X is referred as,the deadly quartet by Kaplan [2] and Foster described it as,a secret killer [3]. Reaven in his Banting Lecture described the point that insulin resistance/hyperinsulinemia might be the underlying cause of the syndrome. Reaven also suggested that insulin resistance/hyperinsulinemia was an underlying risk factor for T2D, which, at the time, was referred to as noninsulin-dependent diabetes mellitus. In 1991, Ferrannini et al. [4] in his article published entitled,’ Hyperinsulinemia: the key feature of a cardiovascular and metabolic syndrome,’ described Reaven’s point of view about insulin resistance and metabolic syndrome. Furthermore, use of the term MS acknowledges that this array of factors is associated with abnormal carbohydrate and lipid metabolism. These authors emphasized that insulin resistance was the underlying factor and, once acquired, those with a genetic predisposition would develop all the other aspects of the disorder. Haffner et al. [5] coined the term “insulin resistance syndrome” for the disorder to highlight the fact that insulin resistance preceded other aspects of the syndrome. Some individuals still use the term insulin resistance syndrome but now the term “metabolic syndrome” is more commonly used to describe the aggregation of multiple CHD and T2D risk factors. Metabolic syndrome is a pathophysiological process, meaning that it is either caused by a disease or represents a dysregulation of normal physiological mechanisms occurring due to long standing insulin resistance. The baseline cause of metabolic syndrome is obesity which is mainly due to accumulation of fat. Thus cluster of condition seen in metabolic syndrome are mainly due to fat storage condition and insulin resistance is feature of fat storage condition. Increased plasma free fatty acid concentrations are typically associated with many insulin-resistant states. It is demonstrated in the animal experimental study that fatty acids compete with glucose for substrate oxidation in heart muscle and diaphragm muscle. It is speculated that increased fat oxidation causes the insulin resistance associated with obesity [6-8]. The mechanism proposed to explain the insulin resistance was that an increase in fatty acids caused an increase in the intra mitochondrial acetyl CoA/CoA and NADH/NAD+ ratios, with sub- sequent inactivation of pyruvate dehydrogenase. This in turn would cause intracellular citrate concentrations to increase, leading to inhibition of phosphofructokinase, a key rate-controlling enzyme in glycolysis. Subsequent accumulation of glucose-6-phosphate would inhibit hexokinase II activity, resulting in an increase in intracellular glucose concentrations and decreased glucose uptake. The increase in plasma fatty acid concentrations initially induce insulin resistance by inhibiting glucose transport or phosphorylation activity, and that causes reduction in muscle glycogen synthesis and glucose oxidation resp. The reduction in insulin-activated glucose transport and phosphorylation activity in normal subjects is observed at high plasma fatty acid levels and leading to accumulation of intramuscular fatty acids (or fatty acid metabolites). This appears to play an important role in the pathogenesis of insulin resistance seen in obese patients and patients with type 2 diabetes. Moreover, fatty acids seem to interfere with a very early step in insulin stimulation of GLUT4 transporter activity or hexokinase II activity. Increasing intracellular fatty acid metabolites, such as diacylglycerol, fatty acyl CoA’s, or ceramides activates a serine/threonine kinase cascade (possibly initiated by protein kinase), leading to phosphorylation of serine/threonine sites on insulin receptor substrates. Serine-phosphorylated forms of these proteins fail to associate with or to activate PI 3-kinase, resulting in decreased activation of glucose transport and other downstream events, Any perturbation in these events results in accumulation of intracellular fatty acyl CoA’s or other fatty acid metabolites in muscle and liver, either through increased delivery or decreased metabolism, might be expected to induce insulin resistance.
Author Details:
Dr. Parineeta Samant
Department of Biochemistry, MGM Medical College, Navi-Mumbai, India.
Read full article: bp.bookpi.org/index.php/bpi/catalog/view/50/394/424-1
View More: www.youtube.com/watch?v=MjZ8Wwzzl-s
another one of my experiments with flavours, black sesame muffins topped with candied winter melon or white chocolate buttons. lol, now i know why practically no one sells these . . . grey coloured foods just don’t look very appealing! m likes them so i’ll be making a 2nd batch soon :).
“Taking black sesame seeds can heal all the chronic illness after 100 days, improve skin tone on body and face after 1 year, reverse gray hair after 2 years, and regrow teeth after 3 years.” says the Compendium of Materia Medica, the largest and most comprehensive medical writings in the history of Traditional Chinese medicine (TCM). This herb is also known as Semen Sesami Nigrum and Hei Zhi Ma and related experiments show that the content of vitamin E contained in this herb is the highest in all foods of plant origin. It is well known that vitamin E can promote cell division and delay cell senescence. Long-term use can counteract or neutralize the accumulation of cell senescence substance of “radicals” and then delay aging and extend life expectancy. Of course, its health benefits are far more than just providing vitamin E. So, what is black sesame good for? Are black sesame seeds better than white ones? How to eat it to maximize its health benefits? All the questions related will be answered in this article soon.
What are black sesame seeds?
Actually it refers to dry mature seeds of Sesamum indicum L., a plant under the genus Sesamum of the family Pedaliaceae. It plants are usually harvested during autumn when the fruits at the peak of their ripeness. And next dry them in the sun, knock out of the seeds, remove impurities, and then dry in the sun once again.
It is flat oval, about 3mm long and 2mm wide. Surface is black and smooth or with netted wrinkles. Tip has brown punctate hilum. Seed coat is thin. Cotyledons are two, white, and rich in oil. It has slight odor, sweet taste, and oil aroma.
Main chemical constituents are up to 55% fatty oil, sesamin, sesamolin, sesamol, vitamin E, phytosterols, lecithin, pedaliin, protein, oligosaccharides, planteose, sesamose, and mall amounts of phosphorus, potassium and cytochrome C, folic acid, nicotinic acid, sucrose, pentosan and large amounts of calcium content. In addition, fatty oil mainly contains approximately 48% oleic acid, approximately 37% linoleic acid, palmitic acid, stearic acid, arachidonic acid, and glycerolipid of lignoceric acid.
Black sesame seeds benefits
As mentioned above, there are two types of sesame seeds – black and white sesame seeds. Both of them contain almost the same composition. So, what is the difference between them? By comparison, white sesame seed is better for edible purpose but the black version is preferable if used for medicinal purpose. To be specific, as the tonic black one is good at nourishing the liver and kidney and improving hair growth and hair color while white one is expert in relaxing bowel, nourishing yin and moisturizing to the skin. Besides, black sesame has high nutritional value. It also contains extremely valuable sesamin and melanin. As a result, it is widely used in treating hair loss and grey hair, inhibiting the growth of skin cancer cells from UV rays, lowering blood pressure, helping weight loss, improving fertility, and so on. And its pharmacological actions can reflect these effects well.
Modern pharmacology of black sesame seed
1. It has anti-aging effect, which can postpone the aging phenomenon in experimental animals;
2. Linoleic acid contained can reduce blood cholesterol level and prevent and treat atherosclerosis;
3. Linoleic acid can inhibit the adrenal cortex function to a certain degree in experimental animals;
4. Linoleic acid can reduce blood sugar, increase glycogen content in liver and muscle, but decrease glycogen content in large doses;
5. Fatty oil contained can lubricate intestines and relieve constipation.
Proven black sesame herbal remedies
Based on Chinese Materia Medica, it is sweet in flavor and neutral in properties. It covers three meridians of liver, spleen, and kidney. Basic functions are tonifying liver and kidney, enriching blood to boost essence, and loosening bowel to relieve constipation. Key black sesame seeds uses and indications are liver-kidney deficiency induced dizziness and tinnitus, flaccid lower back and knee, premature graying hair, dry skin, intestinal dryness and constipation, less milk during lactation, carbuncle and eczema, leprosy, scrofula, ulcers, infantile scrofula, burns, and hemorrhoids. Recommended black sesame seeds dosage is from 9 to 15 grams in decoction, tea pills, or powder.
This is a nutritional herb that can boost essence and nourish blood. It is neutral, sweet, delicious, and good for food therapy. One of its representatives is Fu Sang Zhi Bao Dan, or Sang Ma Wan, which comes from Shou Shi Bao Yuan (Protection of Vital Energy for Longevity). This formula combines it with Sang Ye (White Mulberry Leaf) for the treatment of dizziness, premature graying, and weakness of limbs due to kidney essence and blood deficiency or liver and kidney deficiency.
Simple but effective black sesame seeds recipes
As you can see, this is a good healthy vegetable for food and medicine at the same time. Here are some useful tips and convenient cooking recipes for your reference.
1. Sesame walnut porridge. Ingredients: black sesame seed 50g, walnut 100g, and right amount of rice. Directions: smash them together, add in rice and water, and then cook congee. This recipe nourishes liver and kidney and has therapeutic effect for secondary brain atrophy.
2. Sesame fungus tea. Ingredients: raw sesame 30g, fried sesame 15g, and fried black fungus 30g. Directions: grind them into powder and fill the powder into a bottle for future use. 5 grams each time for making tea with boiling water is highly recommended. This tea has therapeutic effect on hemafecia due to blood heat or dysentery as it can cool blood and stop bleeding.
3. Sesame honey. Ingredients: honey 15g, black sesame seed oil 5g, and warm boiled water. Directions: blend them well and take them before breakfast. This recipe works for constipation.
Black sesame seeds side effects and contraindications
Good as black sesame seeds are for hair, overdose or misuse may speed up the hair loss rate and lead to endocrine disorders, manifested as oily scalp, withering hair follicles, or even baldness. And because it can cause diarrhea, its oil cake after oil expression is toxic to livestock and can cause adverse reactions such as cramps, tremors, difficulty breathing, flatulence, cough and suppression. Excessive feeding on calf can cause eczema, hair removal and itching. TCM wise, use it with care in the case of poor appetite and loose stool.
Withering foot death.
Withering abalone syndrome is a disease of the abalone shellfish, primarily found in the black and red abalone species.
First described in 1986, it is caused by the bacterium "Candidatus Xenohaliotis californiensis", which attacks the lining of the abalone's digestive tract, inhibiting the production of digestive enzymes. To prevent starvation, the abalone consumes its own body mass, causing its characteristic muscular "foot" to wither and atrophy. This impairs the abalone's ability to adhere to rocks, making it far more vulnerable to predation. Withered abalone not eaten by predators typically starve.
Withering Syndrome of Abalone: from (www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/fwsab...)
Common, generally accepted names of the organism or disease agent
Withering syndrome (WS), Withering disease, Foot withering syndrome, Abalone wasting disease, Withering syndrome - an intracellular Rickettsiales-like prokaryote (WS-RLP).
Scientific name or taxonomic affiliation
'Candidatus Xenohaliotis californiensis', a proposed new genus and new species of intracellular prokaryote, with morphological characteristics of the class Proteobacteria, order Rickettsiales and family Rickettsiaceae, in the epithelium of the intestinal tract (Gardner et al. 1995, Friedman et al. 2000b to d). Initially, heavy infections of coccidia in the kidney were thought to cause the disease but, a correlation between coccidial infection and withering syndrome was not found (Steinbeck et al. 1992; VanBlaricom et al. 1993; Kuris et al. 1994; Friedman et al. 1997).
Geographic distribution
Coast of California, USA, south of Point Conception and on the west coast of Baja California, Mexico. In Diablo Cove, California (70 km north of Point Conception), disease and mortalities were limited to the immediate vicinity of a warm-water discharge. In 1996, there was evidence that this disease was progressing northward from Point Conception (Altstatt et al. 1996) and possibly as far north as San Francisco, California (Finley and Friedman 2000). In addition, the bacterium (but not withering syndrome) was detected at two locations in northern California (Crescent City and Van Damme) (Friedman and Finley 2003). In surveys of abalone from Baja California, Mexico, this pathogen was detected in high prevalences in the digestive tract of symptomatic and non-symptomatic cultured and natural populations of H. rufescens, H. fulgens and H. corrugata (Cáceres Martínez and Tinoco Orta 2000, Cáceres Martínez et al. 2000, Caceres-Martinez and Tinoco-Orta 2001, Álvarez-Tinajero et al. 2002). Recently, Xenohaliotis californiensis was reported in H. rufescens cultured in Iceland (unofficial report from Gisli Jonsson in an e-mail dated November 8, 2004) and in H. tuberculata cultured in Ireland in 2006 (records of the OIE) and France (Balserio et al. 2006) with no associated mortalities in these cases. However, H. tuberculata experimentally grown in Galicia (NW Spain) from stocks originating in Ireland experienced high mortality (45% to 100%) within 14 months of importation (most mortalities occurring during the spring and summer months) and were infected with X. californiensis but the associated mortalities were attributed to a co-infection with a protistan pathogen (Balserio et al. 2006).
A similar looking disease of unknown etiology has been reported from cultured Haliotis discus hannai on the northern coast of China (Guo et al. 1999). Rickettsia-like organisms have also been reported in the digestive tract of abalone (Haliotis midae) from culture facilities in South Africa with no associated pathology (Mouton 2000).
Host species
Disease most evident in Haliotis cracherodii, however, the disease and pathogen also occurs in Haliotis rufescens, Haliotis corrugata, Haliotis fulgens, Haliotis sorenseni and Haliotis tuberculata and possibly in Haliotis discus hannai and Haliotis midae.
Impact on the host
A lethal disease that affects all sizes of abalone and causes lethargy, retracted visceral tissues, atrophy of the foot muscle (thereby adversely affects the ability of the abalone to adhere to the substrate) and is lethal. Elevated temperatures accelerated disease progression and decreased survival. At 18 to 20 °C, death usually occurs within one month of the appearance of the clinical signs. Diseased abalone consumed 4.4 times less kelp, 1.2 times less oxygen and excreted 3.8 time more ammonia per gram wet weight than did healthy abalone (Kismohandaka et al. 1993). Severe metabolic alterations were detected in abalone before visible atrophy of the foot occurred. Haemocyanin concentration in the blood decreased, glycogen in the foot muscle was depleted, haemocyte abundance was reduced and haemocytes with abnormal morphology increased in wasted abalone (Friedman 1996; Shields et al. 1996). In addition, haemocytes were more chemotactically active but the capability of the stimulated cells to engulf and destroy foreign particles appeared to be compromised and may contribute to mortality associated with the disease (Friedman et al. 1999, 2000a). Mass specific ammonia excretion was observed in affected abalone indicating protein from the foot muscle was being used as an energy source. This conclusion was also suggested by Kismohandaka et al. (1995) who observed severe foot muscle fibre depletion in samples examined using histology. However, no pathogens were found in the muscle or blood tissues.
This disease is associated with mass mortalities of H. cracherodii. Withering syndrome progressively spread throughout the California Channel Islands causing population crashes on six of the eight Channel Islands by 1992 (95 to 100 percent of the H. cracherodii were lost) and closure of the California black abalone fishery in 1993. A dramatic increase in the number of cultured H. rufescens with foot withering syndrome was noticed in conjunction with El Niño - Southern Oscillation (ENSO) elevated seawater temperatures (Moore et al. 1999). However, differences in susceptibility and tissue changes were noted between species with H. cracherodii being more susceptible than H. rufescens and survivors appear to be relatively resistant to the disease (Friedman et al. 2003b).
Diagnostic techniques
Gross Observations: Body mass relative to shell size is smaller than normal. Affected abalone were discoloured (pale) and weakened, and the soft tissues were atrophied and non-responsive to stimuli. In the field, affected abalone can be detached from the substrate by hand and do not attempt to right themselves when turned upside down.
Squash Preparations: Minced pieces (about 2 mm square) of gastrointestinal tract from the posterior portion of the esophagus to the posterior end of the crop were places on a microscope slide, gently pressed into the slide with a second slide and dried with low heat from a blow dryer for 20 min. Dried samples can be prepared for examination immediately or held indefinitely at 4 °C with desiccant. To prepare for examination, the tissue was flooded with a 10 µg per ml solution of Hoechst 33258 (bisBenzimide, Sigma, St. Louis, MO, USA) in distilled water, covered with a coverslip, incubated in the dark for several minutes and viewed at 100 to 400X magnification with a epifluorescent ultraviolet light and filters appropriate for the spectra of 356 nm excitation and 465 nm emission. This staining technique caused the large inclusions of Xenohaliotis californiensis, which are usually difficult to detect in unstained tissue, to fluoresce a bright blue against a black to dull red background. Although the abalone cell nuclei were also fluorescent, they were small ( about 5 µm in length) in comparison to the inclusions (about 50 µm in length). An alternate nucleic acid-specific fluorochrome, propidium iodide (10 µg per ml in distilled water, Sigma), viewed with ultraviolet light and 530 nm excitation and 615 nm emission filters gave similar results (for further details see Moore et al. 2001a).
Histology: Severe foot muscle fiber depletion. Occurrence of extensive infections of Gram-negative intracellular prokaryotes in the epithelium of the intestinal tract, especially in the enzymes secreting cells of the digestive diverticula. The prokaryotes had morphological characteristics of the order Rickettsiales. They were accumulated into intracellular colonies within epithelial cells. Infection of the digestive diverticula is accompanied by a loss of digestive enzyme granules from epithelial cells and apparently by a metaplasia of enzyme secretory cells to cells morphologically similar to epithelial cells lining the gut (Gardner et al. 1995). This pathology in heavily infected abalone is speculated to be the cause of muscle tissue catabolism resulting in the withering disease.
Electron Microscopy: Observation of rod-shaped, ribosome-rich prokaryotes with trilaminar cell walls accumulated into intracellular colonies within membrane-bound vacuoles in the cytoplasm of gastrointestinal epithelial cells.
DNA Probes: The 16S rDNA was amplified, cloned and sequenced. A polymerase chain reaction (PCR) test was developed that specifically amplifies a 160 base-pair segment of the Rickettsia-like pathogen but not four other microbial species isolated from the gut of abalone. Apparently, this PCR test greatly increases the ability to detect the pathogen (Andree et al. 2000). Also, an in situ hybridization test has been developed (Antonio et al. 2000).
Methods of control
Experiments indicate that the pathogen can be transmitted via the water column and did not require direct contact between infected and uninfected abalone (Moore et al. 2000a and 2001b, Friedman et al. 2002). Above normal temperatures seem to have a synergistic effect on the disease (Cáceres Martínez et al. 2000, Moore et al. 2000a, Raimondi et al. 2002). Results of experiments by Friedman et al.(1997) and Moore et al. (2000a and b) indicated that H. cracherodii and H. rufescens, respectively, held at elevated temperatures (20 °C and 18.5 °C, respectively) had higher mortality, more severe signs of WS and more severe infections with the Rickettsia-like prokaryote than those held in cooler waters (13 °C and 14 °C, respectively). Also, the recovery of black abalone populations affected by mass mortalities from foot withering syndrome seemed to be closely linked with temperature. In affected culture facilities, the severity of the disease may be curtailed if water temperatures could be reduced to about 15 °C or less (Moore et al. 1999). Results of subsequent long-term (447 days) experimentation employing fed and starved abalone indicated that the high morbidity and mortality exhibited by infected abalone is a consequence of disease and not direct thermal stress (Braid et al. 2005).
Oceanographic factors that result in elevated seawater temperatures (i.e., ENSO) had a strong negative impact on the recovery of black abalone populations in southern California (Tissot 1995). These elevated temperatures were also associated with a dramatic increase in the number of red abalone with foot withering syndrome in culture facilities in California (Moore et al. 1999). Despite the devastation caused to black abalone populations, a few large, old individuals can still be found and some small juveniles have been seen (Haaker 1997). Also, the research of Tissot (1995) suggests that black abalone populations in southern California may recover with the subsidence of ENSO oceanographic conditions. Genetic structure of black abalone populations in the California islands and central California coast was assessed in order to identify patterns of recruitment in surviving populations (Chambers et al. 2006).
Evidence indicated that the occurrence of Xenohaliotis californiensis in H. rufescens at two new locations in northern California were associated with out-plants of hatchery-reared abalone, suggesting a link between restoration efforts and the present distribution of this pathogen (Friedman and Finley 2003). The detection of the pathogen outside the previous known distribution highlights the need for careful assessment of animal health before restocking depleted populations or transplanting animals for aquaculture.
Intramuscular injection and oral administration of an antibiotic was effective in reducing the losses of infected abalone (Friedman et al. 2003a) and tissue retention of this therapeutant in the digestive gland remained high for a prolonged time (at least 38 days post treatment) (Braid et al. 2005, Friedman et al. 2007). However, other antimicrobials had no measurable affect on the disease (Friedman et al. 2000b).
www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/fwsab...
Nutrition, exercise, sleep, regulatory hormones. Fewer than half the class have testosterone as a major hormone. Nevertheless, starting the day with "joyful" aerobic activities will synergistically elevate thyroxin levels for the whole day even after the epinephrine goes away. This also increases insulin sensitivity. Recall that habits are made and broken over a period of about four weeks or one month. The body "remembers" how much glycogen to store based on activities over the past month. The parasympathetic system and night time hormones work during sleep to initiate elevated myoglobin, RBC production and hemoglobin, increase mitochondial replication, increase collateral circulation and thereby increased aerobic capacity and endurance. This is saying in essence that what we choose to do with some consistency is how we manage our hypothalamic set points. This is a little like docking the Queen Mary. Long term regulation of set points could take years, so we need to find activities that are both enjoyable, aerobic and worth engaging in over the long years. Hiking, running, cycling, tai ji and other such activities that bring about well being brings early rewards and keeps us going over the longer periods necessary for success.
This presents the overview of what is kidney function. We perform in the vicinity of 28 or 30 complete dialysis blood cleanings every day. During sleep as much as 25% of the heat of the body comes from kidney activity. Regulating blood pH, electrolytes, long term blood pressure adjustments, red blood cell levels, activating of vitamin D and Ca++ uptake from the G.I. tract and many other interesting regulatory actions. Like the liver, the kidney deals with detoxification with smooth ER and also has it's own ability to store glycogen. And like the liver, the kidney can be worked very hard and injured by celebratory activities as well as prescribed or non-prescribed drug administration.
Microscopic Photo Showing: The tumor is composed of large clear cells with glycogen and distinct margins. H & E Stain. Jian-Hua Qiao, MD, FCAP, Los Angeles, CA, USA.
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Springtime in Interior Alaska! The wood frogs are awake and mating.
Wood frogs have one of the more impressive survival strategies. In the fall they convert the sugars in their body into glycogen to coat their cell walls so they will not rupture when they freeze. They then borrow into mud or leave litter and freeze into a frogcycle.
They live for 5 years so they perform this magic 5 times.
By the size this appears to be a female full of eggs.
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We had the kids over for the weekend and they found some Wood Frogs (Rana sylvatica).
They know the fairy tale of the "Frog Princess". No, it's not the one where a young woman kisses a frog, who then turns into a prince.
Anyway, we thought it would be more fitting to offer a princess a bed of flowers, rather than only the leaf of an elephant plant (as in the embedded photo).
These frogs were quite small, maybe 1.5 cm for the body (excluding legs).
Wood Frogs hibernate close to the surface and can tolerate the freezing of their blood and tissues. They prepare for this by accumulating urea in the tissues and converting large quantities of glycogen to glucose. This limits the amount of ice that is formed and protects the cells from damage (think antifreeze). Apparently, they can survive even if 2/3 of the water in their bodies freezes.
These photos were taken with a flash (fitted with a diffuser). The flash has created a fair amount of unwanted reflections and I'll try to take photos in natural light.
The frogs were returned unharmed to their habitat.
This image is the exclusive property of its author, Roger P. Kirchen, and is protected by Canadian and international copyright laws. The use of this image, in whole or in part, for any purpose other than the private online viewing, including, but not limited to copying, reproduction, publication (including web sites and blogs), "hotlinking", storage in a retrieval system (other than an internet browser as part of its normal operation), manipulation and alteration (digital or otherwise), transmission in any form or by any means (such as, but not limited to: electronic, mechanical, photocopying, photographing, recording) is expressly prohibited without the prior written permission by Roger P. Kirchen.
All artistic and moral rights of the author are hereby asserted. Copyright © by Roger P. Kirchen. All Rights Reserved.
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On Monday, I noticed a crowd as I was leaving Laurens, Iowa. They were taking pictures (and getting autographs?) of two guys in LIVESTRONG biking outfits. Ah, Lance.
I thought I would just go out into the country, take a leak in the corn field and wait for a pack of riders to catch up with me. Lo and behold, as I emerged from the corn field, Lance's pack rode by, but I was on the left side of the road and a slow moving semi had just pulled out onto the road in front of me in the left lane.
By the time I got under way, the pack was hundreds of yards down the road ahead of me. They were traveling at maybe 17-19 mph as they passed me, so I knew I would have to make a maximal effort to have any chance of catching them, or I would just lose them. Fortunately, I had just had a 1 hour nap plus lunch and had replenished my blood & muscle glycogen and was warmed up. So I hammered for a mile or so and was able to catch up with them.
I know, you're saying, "That could be anybody"...you didn't even photograph his backside. But, why would I tell complete strangers such a fib? I'm telling you because it was one of the true high lites of this RAGBRAI for me; Lance is one of the all time cycling greats... here...on RAGBRAI! To get that close to him and to actually ride in the same pack with him, wow! For more evidence of the veracity of my claim, see the notes and my 2 other pictures of him.
You can see that it is his bike with Bontrager wheels like here and here. And verify also that it is him via the yellow neckerchief inside of the black jersey collar, Livestrong wrist band on the right wrist, the Garmin 305 on his handlebar, yellow tires, yellow custom accents on the TREK frame, yellow accents on the helmet, the black & silver shoes with yellow toe patches, black socks, black & yellow gloves, green water bottle, (and his black wrist watch band in the 2 the other pics of him), just as in my close up pic. Not every detail is in all 3 of my pics and the 2 that I linked to, but many are.
The reason the pic is so bad is that I'm riding on the left hand edge of the road (there is usually a dangerous drop off at the edge of the concrete). Riding shoulder to shoulder with several other bikers in the left lane, steering with one hand, pulling the camera out of a back pocket, removing the plastic bag protecting it, holding and aiming with one hand - no ability to aim thru the viewer or see the LCD screen in the bright sun light. This all makes the situation quite challenging.
A lesson that I learned is to take a whole bunch of pics in situations like this and hope that at least one reasonable one gets taken. I have a 1 Gb SD card, for Pete's sake!
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