Corso, Dawn M. MA, May 2005 Anthropology

A Comparative Study of Pelvic Variability in Relation to Sexual Dimorphism and Geography in Both Modern and Pre-historic Populations

Chairperson; Noriko Seguchi

This project is an attempt to document pelvic variation based on geography and sexual dimorphism. The pelvis has received little attention with respect to population variability around the world, in comparison to the thorough documentation on the human crania. The methods employed repeat those utilized by both Wu et al. (1982) and Davivongs (1963), in order to ensure comparability with their results on populations of the Han and the Australian Aborigines. Twelve variables (ischial length, sciatic notch breadth, sciatic notch depth, OB of greater sciatic notch, acetabular vertical height, horizontal diameter of acetabulum, maximum length of os coxae, iliac breadth, length of pubic symphysis, pubic length, as well as pelvic and sacral chilotic lines) were measured on four different populations, with some repeated due to different measuring techniques. These include prehistoric populations from New Mexico, Utah, and Colorado and a modern day population from New York. Indices were calculated from this data, including the ischio- pubic index, the coxal index, greater sciatic notch index, the chilotic index and an OB index for efficient population comparability. SPSS was used to perform statistical

analysis of these results, including One-Way ANOVA and Post Hoc tests. Results show a clear deviation of means between sexes when considering areas of the pelvis related to the greater sciatic notch as well as the ischium; but overlap exists in every case. The modern collection was the only group showing statistically significant differences to the other groups. Differences in measuring techniques alone are not sufficient to explain the observed variation.