Common characteristics could then be attributed to the last common ancestor and evolutionary scenarios developed to identify the critical changes that had led to the development of modern humans. Darwin, for instance, argued that movement to the ground, bipedal locomotion, which freed the hands, and natural selection resulting from an adaptive system involving tool use, social cooperation, and warfare were all critical components leading to the development of modern humans. Paleolithic archaeologists were faced with the challenge of finding supporting evidence for such scenarios.

During the 1940s, the new evolutionary synthesis had finally done away with goal-directed change by integrating natural selection and migration with mutation and chance. Washburn (1951a, 1951b) integrated this new evolutionary theory into physical anthropology, shifting the emphasis from descriptive anatomy to the analysis of adaptation. In one of the first studies to come from the new physical anthropology, Bartholomew and Joseph B. Birdsell (1953) proposed that the loss of the estrus cycle and continuing mutual sexual attraction among humans demonstrated that the long surviving family was central to human society. These two men suggested that early hominid groups formed stable family groups providing parental care to dependent young. Following physical anthropologist raymond dart’s (1949) suggestion that Australopithecines were dependent on tools for hunting and butchering animals, they proposed that sexual dimorphism was associated with competition among males for females and that aggressive hunting behavior was derived from this dimorphism (Zihlman 1997).

Studies like that of Bartholomew and Birdsell, together with work by Dart, suggested a feedback between large brains, bipedalism, and tool use. Although it is now known that Dart’s interpretation of the Makapansgat faunal assemblage (literally, the animal bones that were excavated at the site) was in error (Brain 1981), his work, together with that of other scholars, set out a methodology for extracting behavioral information from the material debris left in archaeological sites. In the years since 1960, archaeologists have used evolutionary theory to generate different scenarios that can be tested against the Paleolithic record. The best-known example of this research is Isaac’s food-sharing hypothesis.

Isaac noted two major differences between apes and humans: humans may feed as they forage as apes do, but apes do not regularly postpone food consumption until they have returned to their home base; also, humans actively share food as they acquire it (Isaac 1978). Based on these observations, Isaac hypothesised that the HAS and KBS sites at Koobi Fora (East Africa, Kenya) were formed by hominids carrying stones and bones to a site. These differences in turn suggested the existence of provisioning, the existence of home bases, and the sexual division of labor early in human prehistory.

Beginning in the 1940s, African archaeologists also changed the way they excavated sites. The first excavation of a “living floor” by Louis Leakey and mary leakey occurred at olorgesailie in 1943 (Fagan 1981), and it was followed by similar excavations at Isimila by F. Clark Howell (Howell, Cole, and Kleindienst 1962) and Kalambo Falls by j. desmond clark (Clark 1969, 1974).

At Isimila, Howell emphasized artifact variation within one stratigraphic horizon, thereby challenging the concept of progressive typological and morphological development through time (Gowlett 1990). Interest in defining living floors spread from Africa to Eurasia (Isaac 1972b), and a series of excavations in Europe and the Middle East were conducted at a range of sites: for example, Torralba-Ambrona (Howell 1966), Latamne (Clark 1966), Vértesszöllös (Kretzoi and Vértes 1965), ‘Ubeidiya (Stekelis 1966), and Terra Amata (de Lumley 1969). In the Dordogne region in France, Hallam L. Movius (1974) selected Abri Pataud for excavation and adopted a strategy that would allow for the exposure of horizontal surfaces of contemporary occupation.

Conclusion

Among the more recent Paleolithic studies, some seek to provide a more detailed investigation of the patterns of similarity and difference which characterize each division of the record