The Science Behind How Humans Walk | Prehistoric Autopsy | BBC Earth Science

Professor Alice Roberts and biologist Dr George McGavin continue their journey back into our evolutionary past to understand how humans first started walking up straight. With this journey, they meet one of our earliest prehistoric ancestors, Lucy, from a 3.2 million year old species called Australopithecus afarensis - the first recorded species to trade life in the trees for life on the ground. Best of Earth Science: http://bit.ly/EarthLabOriginals Best of BBC Earth: http://bit.ly/TheBestOfBBCEarthVideos Taken from Prehistoric Autopsy (2012) This is a channel from BBC Studios who help fund new BBC programmes. Service information and feedback: http://bbcworldwide.com/vod-feedback--contact-details.aspx