An analysis of the earliest fossil evidence of human lineage – a femur from the six million year old Orrorin tugenensis -- indicates that this species was bipedal. The functional and phylogenetic significance of these remains have been hotly debated since their discovery in 2000. To date, no one has measured and analyzed the shape of these bones and compared them to modern humans, living apes and other fossil hominins. Recently, though, researchers were granted permission to measure the original fossils in Kenya. Their results reveal and confirm bipedal adaptations. The bones closely resemble those from Australopithecus and Paranthropus, circa 3 to 2 million years ago, contradicting the hypothesis that Orrorin is more closely related to Homo than to Australopithecus.