The transition from archaic Homo sapiens to modern Homo sapiens in Europe and the Near East : proximal femoral evidence

There are presently two competing models concerning the transition from archaic Homo sapiens to early modern Homo sapiens. The first has been described as the multiregional evolutionary model and holds that current populations of modern humans are the result, at least in part, of regional evolution of archaic Homo sapiens to early modern Homo sapiens from the same area. The alternative model has been termed the "Noah's Ark" hypothesis. This holds that current populations of modern humans are the result of a single ancestral population that originated in Africa between 140,000 and 290,000 B.P.

The focus of this thesis is on human proximal morphology with an emphasis on a sub-trochanteric expansion of bone which projects laterally from the femur. This has been termed the latero-proximal femoral flange. A study of fossil hominid samples from Europe and the near East have shown that this flange is present without exception on all observed European archaic and early modern Homo sapiens femora and absent on all observed Near Eastern archaic and early modem Homo sapiens femora.

This thesis has two goals: 1. to demonstrate that the flange cannot be explained as a plastic response of the femur to stress and should, therefore, be interpreted as a discrete, probably genetically controlled trait, and 2. to show that the proximal femora data and the pattern of flange presence and absence in the European and Near Eastern fossil samples do not support the replacement hypothesis. To accomplish these goals, hominid proximal femora of archaic and early modern Homo sapiens from Europe and the Near East were analyzed and selected measurements reported. In addition, two samples of adult American Indians and two samples of Infant American Indians from the Archaic and Mississippian culture groups were analyzed. These were used as comparative samples to document the variability in presence and absence of the flange and its possible relationship to proximal femoral morphology.

Using both univariate and multivariate statistics, it was found that presence of the flange cannot be positively correlated to sex of the individual, or size of the proximal femur. Furthermore, its presence on 34.35% of the combined archaic and Mississippian Indian infant samples demonstrates little likelihood that the flange is a developmental response to stress on the proximal femur, but is instead a genetically controlled feature. In conjunction with the metric data, the pattern of flange presence and absence in the fossil femora from Europe and the Near East strongly suggests regional continuity in each of these areas.