The intense media coverage of new developments in human evolutionary studies testifies eloquently that to our egocentric species no subject is of greater interest than our own past. Yet up to now no comprehensive encyclopedia dealing with the evolution of humankind has been available. In the hope of providing such a source we have worked with our contributors and with Garland Publishing, Inc., to produce the present volume. We have defined human evolution in its broadest sense and so have covered such areas as systematics, evolutionary theory, genetics, primatology, primate paleontology, and Paleolithic archaeology in an attempt to provide the most complete context possible for the understanding of the human fossil record. The contributions in this volume are written to be accessible to those with no prior knowledge of the subject, yet they contain sufficient detail to be of value as a resource to both students and professionals. The work should prove useful to the widest possible range of individuals interested in human evolution. Each entry has been prepared by a leading authority on its subject; and although every contributor was asked to represent all major points of view on the many topics that are the matter of dispute, each was left free to expound his or her preferred interpretation. The volume thus samples the heterogeneity of opinion that gives paleoanthropology so much of its liveliness, while remaining both authoritative and comprehensive.