Loss of land-based vertebrates is accelerating, study finds

In 2015, Stanford biologist Paul Ehrlich coauthored a study declaring the world's sixth mass extinction was underway. Five years later, Ehrlich and colleagues at other institutions have a grim update: the extinction rate ...

Are we really in a sixth mass extinction?

As a philosopher of science, Alisa Bokulich grapples with weighty questions like, how can scientific models represent a system as complex as the Earth? How can we reconstruct Earth's 4.5-billion-year history using only the ...