with Greg Gerdeman and Andrea Giuffrida

This project examines the hypothesis that endurance running (ER) played an important role in human evolution. We are testing the hypothesis that neurobiological rewards associated with running (e.g., the "Runner's High") evolved to motivate and reward ER in humans and cursorial mammals. If true, these results would be powerful support for the notion that selection acted on humans to improve ER performance.

with Herman Pontzer and Mitch Irwin

In collaboration with several colleagues, we are currently measuring total daily energy expenditures of a range of primates including great apes and lemurs. These projects will examine the role of energetics in the evolution of primate life history, ecology, and ranging patterns. We hope to build a large database of primate field energetics to examine broad scaling problems within the Primate order.

with Herman Pontzer and Michael Sockol

This project explores the biomechanics and energetics of chimpanzee bipedal and quadrupedal locomotion. Kinematic, kinetic, and energetics data are combined to identifiy the determinants of chimpanzee costs of locomotion during different locomotor modes. We hope to apply this new understanding of chimpanzee locomotion to the fossil record to understand whether energetics could have played a role in the evolution of human bipedalism.

with Daniel Lieberman and Dennis Bramble

I am collaborating with colleagues in various studies examining the role of endurance running in the evolution of humans. We are currently interested in mechanisms used by humans to stabilize the head and trunk during running. We use a combination of electromyography, kinematics and kinetics to explore differences in stabilization during walking and running in humans and other cursorial mammals.

with William Harcourt-Smith and Case Brown

We are currently performing a detailed examination of the Laetoli footprints to shed light on early hominid locomotor kinematics. Human subjects walk and run through different substrates and their footprints are analyzed using a 3D laser scanner. We use GIS technology to compare the human prints with those from Laetoli.

with Herman Pontzer and Steig Johnson

In collaboration with TenXys Inc., we are developing new technologies to asess locomotion and physiology in field settings. These new technologies are collar based and will be employed on a wide variety of taxa to understand how primates expend energy in their natural habitats. Does the amount of energy they expend on locomotion change when resources become scarce? Does habitat disturbance influence energy balance?

with Liza Shapiro

My dissertation research focused on the effects of limb mass distribution on the locomotor mechanics and energetics of primates. Researchers have long speculated that heavy hands and feet should lead to relatively large locomotor energetic costs due to large limb mass moments of inertia. I examined locomotion in infant baboons as they aged, and their limb mass distirbutions changed. The results of this study suggest that animals with distally heavy limbs may employ novel kinematic mechanisms to mitigate the negative energetic consequences of distal limb mass.

With Liza Shapiro, I continue to explore the relationship between morphology and locomotion by examining how changes in anatomy during ontogeny may influence changes in gait patterns.