Extinct Tree-Climbing Human Walked with a Swagger

A recently unearthed extinct human species — perhaps the most primitive ever discovered — had hands and feet adapted for a life both on the ground and in the trees, researchers say. Although modern humans are the only human species alive today, other human species once walked the Earth. The most recently discovered human species, Homo naledi, had a brain about the size of an orange, but it nevertheless possessed enough of a mind to perform ritual burials of its dead.