By contrast, when a chimpanzee tries to walk upright, its feet stay wide apart, its center of gravity shifts side-to-side, and it awkwardly teeters for only a short time. Lucy and other members of ...

Walking and running upright on two feet as humans do requires ... human skeleton and stride and that of our closest cousins, the chimpanzees, however. On the ground, chimpanzees use a ...

can still walk upright.” He also stressed that the Ulas’ form of quadrupedalism differs from that seen in our closest animal relatives – chimpanzees and gorillas – in one key way.