Fifty Years Ago, Proof Emerged of an Extinct Human Ancestor's Bipedal Walk

Evidence gathered from fossils indicates that man could walk 3 million years ago, according to a Science News report from February 16, 1974.

A skull fragment, shin, and thigh bones belonging to a 3 million-year-old hominid in Ethiopia were discovered by anthropologist D. Carl Johanson. Johanson confirmed these remains belonged to a member of the Australopithecus genus, often referred to as 'ape man'. "We have absolute, concrete evidence that our ancestors walked on two legs over 3 million years ago,” Johanson, then aged 30, said at a press briefing.

The exact point in the evolution of humans when upright walking began is still heavily discussed. Analyses of fossils assume that several species of hominids walked on two legs between 5 million to 7 million years ago. Scientists pointed out in 2022 that an upper leg bone from Sahelanthropus Tchadensis, the oldest known hominid at 7 million years old, showed indications of upright walking, including an inner projection close to the hip joint. However, not all paleoanthropologists are sure that these features provide definitive proof of bipedalism. Some even theorize that the bone might have belonged to an ape that occasionally walked upright.