Ethiopian anthropologist D. Carl Johanson made a groundbreaking discovery of a 3-million-year-old man’s skull fragment, shin and thigh bones, belonging to an ape man (hominid) of the genus Australopithecus. The 30-year-old scientist announced at a news conference, “We have absolute, concrete evidence that our ancestors walked on two legs over 3 million years ago.”
Fossil analyses suggest that several hominid species ambled around on two legs about 5 million to 7 million years ago. An upper leg bone of the oldest known, 7-million-year-old Sahelanthropus tchadensis, bears signs of upright walking including an inner projection near the hip joint, scientists reported. However, not all paleoanthropologists are convinced those features prove a two-legged gait. Some scientists think the bone belonged to an ape that may have walked upright at times.
The findings challenge the belief that humans evolved to walk upright only recently. The discovery of such early evidence raises questions about when and how humans began walking on two legs. The study also sheds light on the evolutionary path of our ancestors and their relationship with apes.
Questions or comments on this article can be directed to firstname.lastname@example.org. Previously the staff writer for physical sciences at Science News, Maria Temming is now the assistant editor at Science News Explores. She has bachelor’s degrees in physics and English