Dissertation Research: A Quantitative Assessment of Frontal Bone Morphological Variation in Middle Pleistocene Homo Using Fourier Analysis

Washington University, Saint Louis MO

Investigators

Abstract

The evolution of our genus during the Middle Pleistocene is a point of contention. Some view geographically dispersed, morphologically differentiated populations as members of a single species. Others interpret morphological variation among groups as signifying species level differences. The frontal bone is an element that can provide significant data in attempting to decide between these two models as it provides data regarding alterations in two regions of the skull: the neurocranium and the splanchnocranium. Additionally, traits of the frontal are used to distinguish Homo erectus and Homo sapiens. This research will utilize a morphometric procedure, Elliptical Fourier Function Analysis to quantify the morphology of the frontal bone in a sample of 'archaic" Homo specimens (including Neanderthals) dated to the Middle Pleistocene. Boundary outline data of coronal, mid-sagittal and parasagittal slices of the frontal bone will be collected and quantified. To establish temporal trends neighboring Early and Late Pleistocene frontal bones will be quantified. Geographic variation will also be ascertained in twenty modern humans from each of nine populations coincident with the fossils. Analysis of the hypotheses will clarify how features of the frontal bone are interrelated as character complexes and how these characters reflect potential sources of variation such as gender and size. This research will contribute to more informed inferences about hominid evolution in the Middle Pleistocene.