My research seeks to reconstruct the evolution of fossil apes and humans, particularly as it relates to the evolution of locomotor behaviors.
 
I am currently working on reconstructing the evolution of pelvic shape in apes and humans, a large-scale project that is funded by the Leakey Foundation (2015-2016) and the Wenner-Gren Foundation (2016-2017). My study is quantifying phenotypic variation in pelvis shape across anthropoid primates, including newly available fossil pelves, using a 3D geometric morphometric approach. As the study moves forward, the expected pelvic shapes for different last common ancestors (LCAs), and considering different phylogenetic and evolutionary scenarios, will then be quantitatively reconstructed at internal nodes in the hominid tree and rendered using novel visualization approaches. This study will allow me to model and measure the amount and directionality of pelvic shape change within each lineage in order to evaluate claims for convergence in pelvic morphology in extant great apes.
Another major on-going endeavor is also my long-term career objective: the discovery, description, and analysis of new fossil primates from East Africa. The Eastern African Rift System is the most important place in the world for understanding primate and human evolution. My research in the region has focused on the Omo-Turkana Basin (southern Ethiopia-northern Kenya), where I have worked since 2009, because it has primate-bearing deposits spanning the entire time period during which apes and hominins evolved (late Oligocene through the late Pleistocene). At the earliest end of this time period, I am describing hominoid-like fossils from the late Oligocene (~24-28 Myr) Eragaleit Beds of Losodok, Kenya, at the gracious invitation of Meave and Richard Leakey. At the most recent end of the timescale, I am assessing the adaptations of the earliest anatomically modern Homo sapiens (195 kyr) from the Kibish Formation, Ethiopia, in collaboration with John Fleagle. Continuing paleontological field research remains a fundamental priority for me, and I hope to continue field projects in the Omo-Turkana Basin and also initiate projects in unexplored localities. 

Approaches

Traditional Morphometrics

I use traditional quantitative techniques, such as calipers and microscribes, to  characterize phenotypic variation in living and fossil primates.

Novel Morphometric Techniques

I have developed and published techniques for non-landmark based morphometrics (with Carol Ward, Mike Plavcan, and the Center for Advanced Spatial Technologies).

Paleontology

I am actively working at fossil sites in East Africa to address paleoanthropological questions. I have previously worked at sites in Kenya, South Africa, and Spain.

Live Animal Work

I have in vivo hip joint mobility data for great apes, hylobatids, and Old and New World monkeys. Most of these data are for captive animals, but I have some free-ranging monkey data available.

Extant Primate Anatomy

I have dissected hip and gluteal regions for all of the great apes (except mountain gorillas), and have contributed soft tissue descriptions to an atlas on bonobos and several forthcoming publications.

Paleosimulations and Visualizations

I developed and published techniques for modeling joint mobility in primates.  I use scanners (laser, structured light, CT and MRI) for anatomical visualizations.