uncovered two human ancestors who each provide invaluable insight on humans' evolution from tree climbers to upright walkers. At 4.4 million years old, Ardi, short for Ardipithecus ramidus, is mankind ...

Sleeping. It’s a large part of our lives and an essential function that enables our bodies and minds to recharge. While this universal human experience may seem like a biological constant ...

and Zeresenay Alemseged at California Academy of Sciences in San Francisco, Calif. was titled, "Australopithecus afarensis Scapular Ontogeny, Function, and the Role of Climbing in Human Evolution." ...

Their analysis placed the tree-climbing, upright-walking specimen into an evolutionary bracket between the unidentified common human-ape ancestor and the line that led to modern homo sapiens.

Humans' ancestors started off with a tail, but about 25 million years ago, they dropped the appendage, leaving it to other tree-dwelling primates like monkeys. But it's not like we've completely ...

According to a recently published study, early human ancestors, specifically Australopithecus ... long arms and curved fingers used for climbing trees. "Although their brains were smaller than ...