A new environmental record for a prehistoric site in Kenya helped researchers figure out how external conditions influenced which of our ancient ancestors lived there, with what way of life.
The last time global carbon dioxide levels were around 400ppm was four million years ago. On average, the world was 3℃ warmer, but in high northern latitudes, it was up to 14℃ warmer than today.
Evidence shows Native Americans in New England lived lightly on the land for thousands of years. It wasn't until Europeans arrived that the landscape experienced major human impacts.
Why did Earth's climate rapidly cool 12,800 years ago? Evidence is mounting that a comet or asteroid collision is to blame, with new support coming from the bottom of a South Carolina lake.