Human Evolution

The rugged landscape created by volcanic eruptions and tectonic plate shifts in east and south Africa millions of years ago may be what prompted our human ancestors to start walking on two legs.

Modern humans' ancestors coaxed onto two legs by rough terrain, study finds

The research challenges the common theory that early hominins - members of the broad human family - were forced onto two feet because climate change reduced the number of trees they could live in. According to the new hypothesis, it is not why they left the forests, but where they went, that explains the evolution.