A sweeping analysis of marine fossils from most of the past half-billion years shows the usual rules of body size evolution change during mass extinctions and their recoveries. The discovery is an early step toward predicting how evolution will play out on the other side of the current extinction crisis.
© SmithsonianA trilobite fossil from the Ordovician period, which lasted from about 485 to 443 million years ago. A new analysis of marine fossils from most of the past half-billion years shows the usual rules of body size evolution change during mass extinctions and their recoveries.
Scientists at Stanford University have discovered a surprising pattern in how life reemerges from cataclysm. Research published Oct. 6 in
Proceedings of the Royal Society B shows the usual rules of body size evolution change not only during mass extinction, but also during subsequent recovery.Since the 1980s, evolutionary biologists have debated whether mass extinctions and the recoveries that follow them intensify the selection criteria of normal times - or fundamentally shift the set of traits that mark groups of species for destruction. The new study finds evidence for the latter in a sweeping analysis of marine fossils from most of the past half-billion years.
Whether and how evolutionary dynamics shift in the wake of global annihilation has "profound implications not only for understanding the origins of the modern biosphere but also for predicting the consequences of the current biodiversity crisis," the authors write.
"Ultimately, we want to be able to look at the fossil record and use it to predict what will go extinct, and more importantly, what comes back," said lead author
Pedro Monarrez, a postdoctoral scholar in Stanford's
School of Earth, Energy & Environmental Sciences (Stanford Earth). "When we look closely at 485 million years of extinctions and recoveries in the world's oceans, there does appear to be a pattern in what comes back based on body size in some groups."
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