Origin Of Bipedalism Closely Tied To Environmental Changes Champaign - May 01, 2002 During the past 100 years, scientists have tossed around a great many hypotheses about the evolutionary route to bipedalism, to what inspired our prehuman ancestors to stand up straight and amble off on two feet. Now, after an extensive study of evolutionary, anatomical and fossil evidence, a team of paleoanthropologists has narrowed down the number of tenable hypotheses to explain bipedalism and our prehuman ancestors' method of navigating their world before they began walking upright. The hypothesis they found the most support for regarding the origin of...