The asteroid collision that may have doomed the dinosaurs 66 million years ago really stank. A new analysis of gases released from vaporized rocks at the impact site in modern-day Mexico suggests that the smashup released up to three times more smelly, climate-cooling sulfur than previously believed. The Chicxulub impact spewed about 325 billion tons […]

Dramatic shifts in the East African climate may have driven toolmaking advances and the development of trading networks among Homo sapiens or their close relatives by the Middle Stone Age, roughly 320,000 years ago. That’s the implication of discoveries reported in three papers published online March 15 in Science. Newly excavated Middle Stone Age tools […]