Doctoral Dissertation Research: Plantigrady in the Primate Foot

Dartmouth College, Hanover NH

Investigators

Abstract

Bipedalism (walking on two legs) is one of the earliest and most critical adaptions that separates humans from other mammals, but there is a lack of consensus about the type of locomotion that preceded it. This doctoral dissertation project will investigate and quantify the structural changes that took place in the ape heel as they relate to plantigrade (heel-striking) adaptations, a critical precursor to becoming bipedal. Locomotor and skeletal data from living animals will be analyzed to better understand the relationship between form and function in our primate and hominin ancestors. This research will contribute to improved science literacy and access within the general public through a combination of public talks, the use of social media to highlight new and engaging research, a commitment to publishing in open access journals, and by providing place-based learning opportunities to connect students living near field sites with local research objectives. This project will also support the mentoring and scientific training of female undergraduates at Dartmouth College and local high school students, as well as the career of a female graduate researcher in a field where women are underrepresented. This project tests the relationship between bone shape and behavior using a multifaceted approach. Kinematic walking data will be collected, using a plantar pressure mat, for semi-wild primates and comparative species, to describe differences in gait with and without plantigrady. Analyses will also include the use of geometric morphometrics and high definition micro-computed tomography (micro-CT) imaging. These data will be used to assess and interpret calcanei across the human lineage and Miocene primate fossil record. By reconstructing the locomotor capabilities of fossil primates, this research will test hypotheses about the polarity of plantigrady within the ape lineage, determine potential selection pressures driving the shift to plantigrady, and use plantigrade behavior to better understand phylogenetic relationships among the many Miocene ape genera and their relation to primates alive today. The project will contribute to our understanding of hominin bipedalism by revealing trends in the locomotor patterns observed just before the advent of the hominin lineage.