B. M. Latimer T. D. White* W. H. Kimbel D. C. Johanson Cleveland Museum of Natural History, Wade Oval, University Circle, Cleveland, Ohio 44106, U.S.A. *Department of Anthropology, University of California, Berkeley, Ca. 94720, U.S.A. C. O. Lovejoy Department of Sociology and Anthropology, Kent State University, Kent, Ohio 44242, U.S.A. Received 12 January 1981 and accepted 25 May 1981 Keywords : Pan paniscus, Australopithecus, hominid evolutionary models. The Pygmy Chimpanzee is not a Living Missing Link in Human Evolution Phylogenetic reconstruction should incorporate knowledge of the fossil record. Recent suggestions that the pygmy chimpanzee can serve as a living missing llnk are contra fossil evidence and are rejected. Recent fossil hominid discoveries in eastern Africa have advanced our knowledge of human evolution. These discoveries furnish essential data bearing on hypotheses of human origins. They have led us to examine claims that modern pongids should be viewed as "living missing links" in the evolution of man. 1. History Huxley (1863) and Darwin (1871) studied human evolution by making anatomical comparisons between living animals. In the virtual absence of a fossil record, it was the only approach available to these early evolutionary biologists. Some evolutionary scenarios are still constructed in this traditional fashion, formulated from a comparative data base but only peripherally including paleontological evidence. Yet any evolutionary hypothesis founded on neontological comparison may ultimately be tested by the fossil record. In this sense, paleontology has been likened to an experimental science--fossil evidence presents a mechanism for testing hypotheses based on comparative evidence of an indirect nature (Le Gros Clark, 1955). Thus, both extant and extinct organisms provide data basic to an understanding of evolution. Darwin pioneered the use of traditional comparative disciplines in evolutionary studies. He was familiar with information derived from anatomy, embryology, physiology, behavior and biogeography. He combined such heterogenous data with the theory of natural selection in his 1871 classic, The Descent of Man. The amount of relevant corn- Journal of Human Evolution (1981) 10~ 475-488 0047-2484181/060475+14 $02.00/0 9 1981 Academic Press Inc. (London) Limited