An Orange a day...

An orange a day keeps the parasitic wasps away.

 

Oranges provide us with vitamin C which has many health benefits. However, as Humans oranges are not detrimental to our survival or fitness.

 

Yet there is an organism who's fitness is depended on oranges.

 

Dorsophila melanogaster commonly known as the fruit fly, prefers to lay its eggs in oranges.

Evolution has gifted the fruit fly with a specific gene that allows it to recognize the scent of oranges (limonene). This adaptation allows fruit flies to recognize oranges and lay their eggs within the fruit. This behavior is an important factor in the reproduction of fruit flies, it reduces the risk of parasitic predation of wasps on fruit fly larvae and thereby increases the probability of the species to pass on its genes to the next generation.

 

Scientists have discovered that when the gene responsible for smelling or “localizing” the scent of oranges is silenced, the fruit fly is not able to locate oranges. By not laying eggs in oranges, the fruit fly larvae are exposed to parasitic wasps who lay their eggs within fruit fly larvae. This is a great example of natural selection. Since the parasitic wasps are deterred by the smell of oranges, fruit flies with the gene responsible for sensing the scent of oranges have a greater chance of producing offspring, while the ones lacking the characteristic are more likely to die off.

 

 

Source:

www.mpg.de/7641278/orangen_schuetzen_fruchtfliegen

 

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