"Mass extinctions, the spatial fossil record, and how paleoecology may help save the planet" by Simon Darroch (Vanderbilt University)

 

A critical challenge for paleontologists in the 21st Century is deciding how to use the fossil record to generate tools relevant to the current biodiversity crisis - the ‘6th mass extinction’. Here, I argue that too much effort has been spent on comparing current rates of species loss with those extrapolated from the past, because species may not need to be extinct for ecosystems to collapse – they may only need to be rare. Instead, the spatial components of past extinctions (changes in geographic range sizes, as well as emergent properties such as beta diversity) may provide a better metric for comparing between modern and ancient crises. Lastly, I discuss evidence for an Ediacaran-Cambrian (~542 Ma) mass extinction – the ‘first mass extinction of complex life’. Unlike the Phanerozoic ‘Big Five’, this extinction may have been driven by evolutionary innovation, ecosystem engineering and biological interactions, providing a powerful analogue for the present day.