New Bones Give Clues to Human Evolution
Why did our ancestors stop moving around on four limbs in the trees and start moving around on two limbs on the ground? This article suggests that 4 million-year-old bones recently found in Ethiopia could provide some clue.
They include a complete tibia from the lower part of the leg, parts of a thighbone, ribs, vertebrae, a collarbone, pelvis and a complete shoulder blade, or scapula.
The fossils also included an anklebone which, with the tibia, proved that the creature walked upright, said Bruce Latimer, director of the Cleveland Museum of Natural History, Ohio, who led the two-month excavation.
'Right now we can say this is the world's oldest bipedal (two-footed) apeman. What makes us human is walking upright,' Latimer said. 'This discovery will give us a picture of how walking upright occurred. It's a once-in-a-lifetime find.'