Evolution of Tree Roots May Have Driven Mass Extinctions
Published:01 Dec.2022 Source:Indiana University
A new analysis showed that the evolution of tree roots likely flooded past oceans with excess nutrients, causing massive algae growth. And the research reported that these rapid and destructive algae blooms would have depleted most of the oceans’ oxygen, triggering catastrophic mass extinction events. The theory is based upon a combination of new and existing evidence, the researchers said.
Based upon a chemical analysis of stone deposits from ancient lake beds -- whose remnants persist across the globe, including the samples used in the study from sites in Greenland and off the northeast coast of Scotland -- the researchers were able to confirm previously identified cycles of higher and lower levels of phosphorus, a chemical element found in all life on Earth. In light of the phosphorus cycles occurring at the same time as the evolution of the first tree roots -- a feature of Archaeopteris, also the first plant to grow leaves and reach heights of 30 feet -- the researchers were able to pinpoint the decay of tree roots as the prime suspect behind the Devonian Periods extinction events.