Bipedalism — walking upright on two legs — us a defining feature of the human lineage. It is thought to have evolved as forests retreated in the Late Miocene to Pliocene period. Chimpanzees living in analogous habitats to early hominins offer a unique opportunity to investigate the ecological drivers of bipedalism that cannot be addressed via the fossil record alone. In new research, scientists focused on a community of eastern chimpanzees...