Scientists have searched for the last several decades to figure out when (and which of) our hominid ancestors made the great leap forward to come "out of the trees" and start walking upright on two legs (a.k.a., bipedal locomotion). The latest estimate is something over 4 million years ago. But, says a new article published in PNAS this week, we've completely forgotten that there are modern humans today that still walk in trees.
Caption: Men in Twa society from Uganda regularly climb trees to gather honey. Photo credit: Nathaniel Dominy
Research by a group led by Dartmouth anthropologist Nathaniel Dominy has recognized that, with training, modern people can still safely climb trees without additional support (just don't try this at home). Significantly, the skill doesn't require a different set of foot and ankle bones (just longer and stronger muscles and sinews) and those improvements have no visible impact on existing foot and ankle bone structures.
So, that being the case: can we actually say that we are today "fully terrestrial"?