"Lucy" Kin Pushes Back Evolution of Upright Walking?
Male human ancestor spent more time on foot than in trees, study says.
Lucy—a 3.2-million-year-old skeleton discovered in 1974—belongs to Australopithecus afarensis, a species which scientists think was an early direct ancestor of modern humans.
An exceptionally petite female—her estimated height was 3.5 feet (1.1 meters)—Lucy's small frame has been interpreted as not being totally adapted for human-like, upright walking.
(See: "6-Million-Year-Old Human Ancestor 1st to Walk Upright?")
But the discovery of the 3.6-million-year-old male disproves that idea, said study co-author Yohannes Haile-Selassie, curator of physical anthropology at the Cleveland Museum of Natural History.
"As a result of this discovery, we can now confidently say that 'Lucy' and her relatives were almost as proficient as we are walking on two legs, and that the