Chimpanzees and the Behavior of Ardipithecus ramidus*

The living great apes and, in particular, the chimpanzee have served as models of the behavior and ecology of earliest hominins for many decades. The reconstructions of Ardipithecus ramidus have, however, called into question the relevance of great-ape models. This paper reviews the ways in which human evolutionary scholars have used field data on the great apes to build models of human origins. I consider the likely behavioral ecology of A. ramidus and the relevance of the great apes for understanding the earliest stages of hominin evolution. I argue that the Ardipithecus fossils strongly support a chimpanzee model for early hominin behavioral ecology. They indicate a chimpanzee-like hominoid that appears to be an early biped or semibiped, adapted to both terrestrial and arboreal substrates. I suggest how paleoanthropologists may more realistically extrapolate from living apes to extinct hominoid behavior and ecology.