Integrative Natural History of Minnesota's North Shore, Part 20: Rooted in Evolutionary Reality | Gooseberry Falls State Park
Taken near the cliffside trail on the western side of the Middle Falls.
This photo complements the Part 19 image, and like it shows one of the park's predominant tree species, Arbor Vitae (Thuja occidentalis) hanging on for dear life on the edge of an outcrop of North Shore Volcanic Group basalt. This igneous extrusive rock is a small part of the immense outpouring of mafic lava that accompanied the development of the late-Mesoproterozoic Midcontinent Rift.
While usually not quite this visible, roots are amazing structures and one of the most geologically significant evolutionary adaptations in the whole history of life.
Before plants developed substantial roots systems, for both better anchoring and vastly more effective uptake of water, oxygen, and nutrients, the Earth was a world where the force of erosion more frequently predominated over the process of weathering.
But as rooted plants spread over larger and larger areas of our planet's surface, they created positive feedback loops ultimately involving the development of true soils, an increase of carbon sequestration in the ground, and an increase in the atmosphere's free-oxygen content. All these things had further dramatic effects on climate, rock formation, and the development of other living communities.
So when did roots first evolve? Most paleobotanists think that plants had developed them by the early Devonian period, approximately 400 Ma ago. That may seem an ancient date indeed, but keep in mind that the basalt to which this tree clings is, at 1,100 Ma, almost three times as old.
To see the other photos and descriptions of this series, visit
my Integrative Natural History of Minnesota's North Shore album.
Integrative Natural History of Minnesota's North Shore, Part 20: Rooted in Evolutionary Reality | Gooseberry Falls State Park
Taken near the cliffside trail on the western side of the Middle Falls.
This photo complements the Part 19 image, and like it shows one of the park's predominant tree species, Arbor Vitae (Thuja occidentalis) hanging on for dear life on the edge of an outcrop of North Shore Volcanic Group basalt. This igneous extrusive rock is a small part of the immense outpouring of mafic lava that accompanied the development of the late-Mesoproterozoic Midcontinent Rift.
While usually not quite this visible, roots are amazing structures and one of the most geologically significant evolutionary adaptations in the whole history of life.
Before plants developed substantial roots systems, for both better anchoring and vastly more effective uptake of water, oxygen, and nutrients, the Earth was a world where the force of erosion more frequently predominated over the process of weathering.
But as rooted plants spread over larger and larger areas of our planet's surface, they created positive feedback loops ultimately involving the development of true soils, an increase of carbon sequestration in the ground, and an increase in the atmosphere's free-oxygen content. All these things had further dramatic effects on climate, rock formation, and the development of other living communities.
So when did roots first evolve? Most paleobotanists think that plants had developed them by the early Devonian period, approximately 400 Ma ago. That may seem an ancient date indeed, but keep in mind that the basalt to which this tree clings is, at 1,100 Ma, almost three times as old.
To see the other photos and descriptions of this series, visit
my Integrative Natural History of Minnesota's North Shore album.