Studs talks with Donald Johanson about his book "Lucy: The Beginnings of Humankind," in which the famed paleoanthropologist describes his discovery of the female hominin fossil in Ethiopia. The conversation includes talk of Charles Darwin, Eugène Dubois' Java Man discovery, what makes a hominid, holes in the fossil record, fossil dating, his disagreements with Louis and Richard Leakey, site discovery, and his belief that the Hadar Formation in the Afar Triangle of Ethiopia holds the keys to the evolutionary puzzle. Includes snippets of the Beatles' "Lucy in the Sky with Diamonds."

Evolution and the future of the human race are among topics in Carl Sagan's and Ann Druyan's book, "Shadows of Forgotten Ancestors: A Search for Who We Are." Included is an excerpt of the astronomer Harlow Shapley speaking at the beginning. Carl Sagan also reads an excerpt from the book at the end.

The archaeologist and author discusses the controversial theory that modern humans may have originated in North America, further explored in his book, American Genesis.*Please note: some sections have been edited out from the original recording due to copyright considerations