the earliest hominines

…

…Perhaps for: carrying foraged foods from place to place carrying infants so that fatal falls from mother were minimized; faster food gathering and longer treks with less fatigue; spotting food sources or predators from a distance with the increased height and visual perspective of standing on the hind limbs; or freeing hands to fend off predators by using natural objects as weapons. In any case, the bipedal adaptation was likely the result of several factors.