Professor of anthropology at the University of California, Los Angeles, Joan B. Silk studies the evolution of primate behavior and applies evolutionary models to the study of human behavior. She has conducted extensive research on the social lives of monkeys and apes, including extended fieldwork on chimpanzees at the Gombe Stream Reserve in Tanzania and baboons in Kenya and Botswana. Her recent work explores the phylogenetic roots of pro-social preferences and looks at the evolution and function of relationships, such as human friendship, that seem to transcend the calculus of kin selection and reciprocity. Dr. Silk earned a B.A. with honors in anthropology at Pitzer College in Claremont, California, and went on to study on a Regents Fellowship at the University of California, Davis, where she took her Ph.D. in anthropology in 1981. She studied biology at the University of Chicago on a National Science Foundation postdoctoral fellowship and a National Service Research Award from the National Institute of Mental Health. She went to Duke University in 1983 as a visiting scholar in zoology and the following year joined the anthropology faculty of Emory University as an assistant professor and, at the same time, worked as an assistant research behaviorist at the California Primate Research Center (CPRC) at UC/Davis. She was named an affiliate scientist at the CPRC in 1986. She accepted appointment as an associate professor of anthropology at UCLA in 1990 and was named a full professor five years later. Dr. Silk currently chairs the department. She has been a fellow at the Zentrum für Interdisziplinäre Forschung at the University of Bielefeld in Germany and a visiting fellow at the Leverhulme Centre for Human Evolutionary Studies at Cambridge University, as well as a visiting professor in zoology at Cambridge and a visiting professorial fellow at Magdalene College, Cambridge. An elected fellow of the American Anthropological Association and of the Animal Behavior Society, she serves on the scientific executive committee of the Leakey Foundation and on the scientific advisory board of the Courant Research Centre for the Evolution of Social Behaviour at the University of Göttingen. She is currently a member of the editorial board of Human Nature, a member of the advisory board of Primates, consulting editor of Human Behavior and Evolution, and associate editor of Behavioral Ecology and Sociobiology. The author of more than 100 papers published in scientific journals or as contributions to volumes of collected works, Dr. Silk is the co-author (with Robert Boyd) of How Humans Evolved, which was originally published by W.W. Norton in 1997 and has subsequently appeared in four revised editions and been published in French and Spanish.