DISSERTATION RESEARCH: Constraints on Primate Craniofacial Growth and Form

George Washington University, Washington DC

Investigators

Abstract

The mammalian skull is an integrated complex of overlapping units that are involved in multiple functions such as breathing, vision, hearing, smelling and swallowing. Therefore most morphological features in the skull tend to be considerably inter-correlated, limiting variation. Non-independent cranial features, however, are problematic for reconstructing evolutionary relationships, because they subjectively bias efforts to group most-closely related species. This study uses CAT scans and radiographs of primate skulls to test several hypotheses about interrelationships between the brain, cranial base and face in primates, in order to assess specifically the utility of skull characters for reconstructing evolutionary relationships in primates and human ancestors. Univariate, bivariate and multivariate techniques, including scaling and matrix analyses, will be used to test patterns of constraint and integration among skull characters in 70 primate species and growth samples of 10 species of monkeys and apes. Preliminary results suggest that constraints which result from integration, while rare, considerably affect variations in primate skull form and should be taken into account when testing phylogenetic hypotheses about primate and human evolution.