October 2, 2012
A dramatic rise in atmospheric oxygen levels has long been speculated as the trigger for early animal evolution. In the Sept. 27 issue of the journal Nature, researchers for the first time offer evidence of a causal link between trends in early biological diversity and shifts in Earth system processes.
The fossil record shows a marked increase in animal and algae fossils roughly 635 million years ago. Researchers, including sustainability scientist Ariel Anbar, believe that oceanic oxygen levels spiked suddenly at this time, in the wake of a severe glaciation, reaching the level necessary to allow animals to flourish. The new evidence pre-dates previous estimates of a life-sustaining oxygenation event by more than 50 million years.