Non-metric cranial and mandibular trait frequency patterns and their implications for modern human origins

Currently, the evolutionary origins of Homo sapiens can be described as one of the most controversial debates within the discipline of Paleoanthropology. Of the more prominent theoretical models in the debate is the Multiregional Evolution hypothesis (Wolpoff 1984, 1985). This model suggests Homo sapiens arose among regionally diverse populations of archaic hominids, asserting a universal evolutionary trend among archaic hominid populations toward anatomically modern humans. On the other hand, the Recent African Origin model predicts that the establishment of Homo sapiens beyond the African continent and into Europe and Asia as due only to population replacement This model predicts that there will be no transitional fossils found outside of Africa (Stringer and Andrews 1988).

The conflicting predictions generated by these competing hypotheses are tested by this project. The Multiregional Evolution model's prediction of regional continuity is treated as the null hypothesis because it is the simpler of the two models. It assumes only that regional archaic populations evolved, at least in part, into their modern counterparts. The Recent African Origin hypothesis is theoretically a more complex model, assuming all modern non-African hominids are the product of population replacement. This model posits multiple hominid specifications.

By utilizing specific non-metric features morphological variation is reduced to merely the question of presence or absence. Utilizing Fisher's Exact Test, the analysis offers statistically legitimate results even with the limitations incurred by a numerically limited sample of archaic hominids. The overall, discernible trait frequency patterns do not support arguments of complete genetic replacement. Thirty-three percent of characteristics recognize a purported mtra-regional similarity with specific morphological features.