Evolution of Early Human Body Form

Upright walking is the hallmark of human evolution, with the earliest definitive hominins showing adaptations throughout their skeletons for habitual terrestrial bipedality.  Yet the earliest committed bipeds, the australopiths, were not built exactly like the members of our genus, Homo.  It has traditionally been argued that this means climbing trees was still important for australopiths, and the shift to a more fully human-like body plan signaled the abandonment of tree-climbing, even though there may be other adaptive explanations.  Furthermore, the earliest members of the genus Homo were not as human-like in all ways as we had thought, and new fossil evidence of hominin diversity suggest that there was not a single transition to human-like body form in early Homo.   Taken together new fossils and new perspectives may be changing our ideas about the origins of our genus.