Evolution of modern diversity in human pelvic form: biological, statistical, and political controversies


Philipp Mitteröcker

Unit for Theoretical Biology, Department of Evolutionary Biology
University of Vienna


Many studies in evolutionary biology and anthropology addressed whether morphological differences among human populations evolved by natural selection or drift. The human pelvis has received much attention in this regard. Despite a rich literature on the functional relevance of pelvic geometry for parturition, support of inner organs and the fetus, locomotion, and thermoregulation, recent papers claimed that population differences in pelvic form mainly arose by neutral evolution, without considerable natural selection. By drawing from evolutionary quantitative genetics, I derive a number of expectations for phenotypic traits under neutral and adaptive evolution in geographically structured environments, and I present a reanalysis of published data on pelvic canal diameters. For all analyses, I arrive at the exactly opposite conclusions as those previously published: pelvic dimensions diverged much more across populations than expected under neutral evolution, suggesting an important role of natural selection in the evolution of modern pelvic form variation. Finally, I will discuss the important role of theory-driven data analysis in evolutionary biology and the growing concerns of social scientists (and an increasing number of biologists) about adaptive views of human biology.