Doctoral Dissertation Research: Comparison of arboreal locomotion in ecologically distinct primate populations

George Washington University, Washington DC

Investigators

Abstract

The skeletal anatomy of an animal species is generally related to its patterns of movement and behavior and to its habitat. Understanding the complex relationships between form, function, and environment is essential for reconstructing the behaviors and habitats of past species. This doctoral dissertation project will investigate how populations of wild mountain gorillas living in ecologically distinct habitats may differ in their patterns of movement (locomotor behavior). This information will help contextualize the observable skeletal variation in apes and inform our inferences about locomotion in fossil apes and humans. The project will involve interdisciplinary and international collaborations, broaden the participation of under-represented groups in STEM, and provide research mentorship to undergraduate students. The researchers will engage with the public on topics related to human evolution and our closest living relatives, the African apes. Paleoanthropologists have long debated how our early ancestors moved, especially in terms of how they first began walking upright on two legs, and how much time they may have spent in the trees. While more fossils, and more species, have been added to the hominin family tree, there is still limited knowledge about how closely related species and populations may have differed in terms of habitats and locomotion. Data on the locomotion of living ape populations can advance our understanding of the form-function relationships between locomotor behavior and skeletal features, allowing more informed inferences from the ape and human fossil record. The researchers will investigate how the locomotor behavior of two populations of mountain gorillas differs, in terms of the frequency of key locomotor behaviors and limb and joint motions. The study will use traditional observational methods to quantify the relative frequency of different postural and locomotor behaviors, and place into context the frequency of locomotor behaviors (e.g., vertical climbing and below-branch suspension) in comparison to other great apes. The video-based motion analysis (kinematics) will implement new field-based methods for capturing motion data, providing some of the first 3D kinematic data on apes in their natural environment. Kinematic analysis will quantify the joint postures and movements used during locomotion, offering new quantitative data for interpreting the functional role of skeletal features often used to infer locomotor capabilities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.