About the Author

G. J. Sawyer is senior scientific technician, Esteban Sarmiento is research associate, and Ian Tattersall is curator, all in the Division of Anthropology of the American Museum of Natural History. The authors live in New York City. Studio V is located in Connecticut. Donald C. Johanson is Virginia M. Ullman Chair in Human Origins, professor, department of anthropology, and director, Institute of Human Origins, at Arizona State University. Meave Leakey is research associate, National Museums of Kenya, adjunct professor, Stony Brook University, New York, and Explorer-in-Residence, National Geographic Society.