Standing on Their Own Two Feet

It has been generally assumed that the humanoid bipedal mode of locomotion, was largely an adaptation to life on the ground, as our arboreal ancestors 'came down from the trees'. The Common chimpanzee is our closest non-human relative. Wild chimpanees in Africa, were subject to detailed posture analysis (https://www.theguardian.com/science/2022/dec/14/bipedalism-foraging-research). Some of the study groups lived in densely-wooded areas, whereas others were more grasslands-based. Irrespective of the type of habitat, the study showed that only a tiny percentage of bipedal postures occurred on the ground. Most of the times the chimpanzees were on two legs, they were in a tree. The authors of the study suggest that early humans adopted bipedal locomotion, to forage for food in trees. This is in direct contrast to the earlier assumption. We will, of course, never know for certain.