In 1959, scientists excavating at Olduvai Gorge in Tanzania found fossils that they believed belonged to the earliest member of the human family—a creature known as Homo habilis, which lived 2.3 million to 2.4 million years ago. In the past decade, however, researchers have analyzed the bones of H. habilis with new methods, finding that in many ways this species was still eating and developing more like an ape than a modern human. So just who were the first humans? What do recent findings tell us about how our species evolved? And what new discoveries are changing our thinking about where we came from?
Join us for a live chat at 3 p.m. EDT on Thursday, 23 June, on this page about the origins of the first human. You can leave your questions in the comment box below before the chat starts.
William Kimbel is the director of the Institute of Human Origins at Arizona State University. He conducts field, laboratory and theoretical research in paleoanthropology, with a primary focus on Plio-Pleistocene hominid evolution in Africa. He is also interested in the application of evolutionary and systematic theory to paleoanthropological problems.
Peter Ungar is chair of the Department of Anthropology at the University of Arkansas. His research interests focus on paleoecology, and more specifically, the evolution of dietary adaptations in early human ancestors and other fossil mammals.