In this new fourth edition, Campbell has revised and updated his classic introduction to the field. Human Evolution synthesizes the major findings of modern research and theory and presents a complete and integrated account of the evolution of human beings. New developments in microbiology and recent fossil records are incorporated into the enormous range of this volume, with the resulting text as lucid and comprehensive as earlier editions. The fourth edition retains the thematic structure and organization of the third, with its cogent treatment of human variability and speciation, primate locomotion, and nonverbal communication and the evolution of language, supported by more than 150 detailed illustrations and an expanded and updated glossary and bibliography. As in prior editions, the book treats evolution as a concomitant development of the main behavioral and functional complexes of the genus Homo among them motor control and locomotion, mastication and digestion, the senses and reproduction. It analyzes each complex in terms of its changing function, and continually stresses how the separate complexes evolve interdependently over the long course of the human journey. All these aspects are placed within the context of contemporary evolutionary and genetic theory, analyses of the varied extensions of the fossil record, and contemporary primatology and comparative morphology. The result is a primary text for undergraduate and graduate courses, one that will also serve as required reading for anthropologists, biologists, and nonspecialists with an interest in human evolution.