Video: Digging for humanity's origins

Louise Leakey asks, "Who are we?" The question takes her to the Rift Valley in Eastern Africa, where she digs for the evolutionary origins of humankind -- and suggests a stunning new vision of our competing ancestors.

Louise Leakey is the third generation of her family to dig for humanity’s past in East Africa. In 2001, Leakey and her mother, Meave, found a previously unknown hominid, the 3.5-million-year-old Kenyanthropus platyops, at Lake Turkana -- the same region where her father, Richard, discovered the "Turkana Boy" fossil, and near Tanzania’s Olduvai Gorge, where her grandparents, Louise and Mary Leakey, discovered the bones of Homo habilis.