When we look at other primates, although the similarities are clear, there are also several stark contrasts. Most noticeable, is our gait – humans are the only truly bipedal (upright walking) primates. Bipedality appeared early in human evolution, and may have marked our divergence from Chimpanzees around 6 million years ago. Bipedality had a number of benefits, allowing us to adapt to a new habitat, and freeing up our hands for other tasks, but compromises also had to be made. Changes in the shape of our pelvis, which enabled us to walk upright, also made childbirth considerably more dangerous and complex. Nevertheless, bipedality is thought to have facilitated the marked advances in tool use and gestural communication that are hallmarks of the human condition.