My current research centers around the problem of how behavior can reliably be inferred from skeletal structure, with special focus on the origin and evolution of human locomotion and craniofacial biomechanics. My long-range goals include the recovery and analysis of relevant fossils, and investigating the factors influencing bone morphology during growth with the aim of improving our understanding of the adaptive history of human evolution. Problems of particular interest include the origins of bipedality and how it changed in subsequent hominids, the abandonment of arboreality, the evolution of limb proportions, the biomechanics and origin of tool use, and craniofacial adaptations for diet in hominid evolution.

My main current research projects include paleoanthropological fieldwork in Koobi Fora, Kenya, an investigation into the relation between function and trabecular bone structure, an interdisciplinary project investigating primate craniofacial biomechanics through finite element modeling and strain gage analysis.

Paleontology Fieldwork

New fossil discoveries form one of the foundations of our understanding of human evolutionary history, as they provide raw data about the past. I have been involved in field research in Turkey, Ethiopia, and am currently conducting research in Plio-Pleistocene sediments in Koobi Fora, Kenya.

Trabecular Bone Functional Morphology

Researchers continue to disagree over how to reconstruct the locomotor behavior of fossil hominins mainly because some interpret apelike features of the hominin skeleton as evidence of apelike behavior, while others interpret the apelike features as primitive retentions with little or no functional relevance. Because experimental data show that trabecular bone structure (the spongy bone matrix within joints, as seen in this image) is related to functional loading of joints, analysis of 3D trabecular structure offers a new way of testing longstanding hypotheses about the evolution of locomotor behavior in fossil hominins. Our current research investigates specific details of the relationship between functional loading and trabecular bone structure, and the structure in fossil hominins and comparative extant species.

Supported by the National Science Foundation.

Primate Craniofacial Biomechanics

Although there is no doubt that aspects of skull shape are structurally related to resisting the stresses from biting and chewing, relatively little is known about these stresses in primates and humans. As part of a collaborative research project, I am exploring the utility of Finite Element Analysis (FEA), in conjunction with experimental data, in modeling stresses and strains in the primate facial skeleton. This work will help us test hypotheses about how the face and skull are strained during biting and chewing, how variation in biomechanical factors (e.g., bone mechanical properties, and muscle force, geometry, and timing) influence stresses, and how specific aspects of bone structure (e.g., postorbital bar, degree of prognathism) influence stress distributions. Ultimately, FEA promises to be a useful tool for examining the biomechanical significance of unique features of fossil hominid skulls.

Supported by a HOMINID grant from the National Science Foundation.