Rise of Humans: Great Scientific Debates

One of the most famous scientific debates in anthropology took place in the 1970s, with the discovery of fossil remains of a possible Homo ancestor, Australopithecus afarensis. Where exactly did Homo come from? Follow this highly public story from the perspective of the key personalities involved: scientists Don Johanson and Richard Leakey.

In 1994, paleontologists discovered the 4.4-million-year-old remains of Ardipithecus ramidus. Is it a true hominin? What skeletal features suggest the tradeoffs between being an effective climber and walking bipedally? Answer these and other questions by closely examining the fossil and genetic evidence of this fascinating "ground ape."

Your brain separates you more from apes than any other anatomical feature. Investigate the gradual increase in hominid brain size in the fossil record. Looking at what fossil skulls (such as the Taung skull) reveal about blood circulation and cooling, you'll shed new light on brain size and skull structure.

Explore the relationship between diet and morphology in this lecture on Australopithecus robustus and Australopithecus africanus. The teeth and jaws of these two species, you'll discover, offer intriguing windows into the fierce debate surrounding the dietary hypothesis and the true adaptive differences between robust and gracile hominids.

Was Africa or Asia more central to human origins? How can we tell? Drawing on the ideas and theories of prominent scientists, including Charles Darwin, Ernst Haeckel, and Louis Leakey, learn how we found the truth about where our genus Homo came from—and where it evolved.