Donald Johanson has explored the Great Rift Valley of East Africa for more than two decades, seeking clues to our ultimate origins. One of the most lively and controversial scientists working today, he is the author of five previous books, the host of the three-part Nova series In Search of Human Origins, and continues to lecture regularly. Known worldwide for his discovery of the Lucy skeleton, he is founder and president of the Institute of Human Origins in Berkeley, California, where he resides.