Mass extinctions

For millions of years after the end-Permian mass extinction, the same few marine survivor species show up as fossils all over the planet. A new study reveals what drove this global biological uniformity.

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.

A new Stanford University study shows rising oxygen levels may explain why global extinction rates slowed down over the past 541 million years. Below 40 percent of present atmospheric oxygen, ocean dead zones rapidly expand, and extinctions ramp up.

Researchers present new evidence that the deoxygenation of the ocean wiped out biodiversity during one of the “Big Five” mass extinctions in Earth’s history – relevant information as climate change contributes to decreasing oxygen in the oceans today.

Scientists have debated until now what made Earth's oceans so inhospitable to life that some 96 percent of marine species died off at the end of the Permian period. New research shows the "Great Dying" was caused by global warming that left ocean animals unable to breathe.

 Analysis of ancient seabed rocks from disparate locations reveal that life did not rebound until anoxia had fully ebbed.