Functional Morphology of Primate Hind Limbs and their Locomotor Implications

Advisors: Professor Eric Sargis (YPM Curator of Vertebrate Paleontology and Vertebrate Zoology) and Graduate Student Spencer Irvine (YPM Vertebrate Paleontology) 



Length: 6 weeks in the summer 


Project Description: 

Undergraduates are invited to participate in morphological research during the summer of 2021 to work with a curator and graduate student from the Yale Peabody Museum of Natural History (YPM). This project focuses on the adaptive morphology of the primate hip and knee. Extant primates share many skeletal features that relate to the ability to maneuver through the trees. This reflects their evolution from an arboreal ancestor. Living in the trees is challenging and dangerous, requiring specialized morphology to navigate this complex 3D environment. To successfully traverse these habitats, early primates are hypothesized to have employed grasp-leaping locomotion, just as several extant primates do today. This form of locomotion involves grasping hands and feet and relies on powerful hind limbs for leaping across gaps in the canopy. Many of the adaptations in the hind limb for grasp-leaping can be found at the hip and knee joints. 


Although we cannot directly observe the relationship between grasp-leaping locomotion and skeletal morphology in fossil primates, we can use extant taxa as models by comparing the morphology of their hip and knee to that of early fossil primates. The YPM collections contain a variety of primate skeletons that can be analyzed for this purpose. The undergraduate researcher will assist with these analyses in a laboratory setting. Although the work requires the undergraduate to be on campus, training can be done remotely, and lab work can be socially distanced, depending on COVID-19 protocols. This work will help test hypotheses about early primate locomotor behavior and enhance our understanding of primate origins and functional morphology. 


The undergraduate researcher will be involved in multiple aspects of this project. They will learn to use anatomical characteristics to identify and describe primate taxa to address questions such as 1) what is the morphological diversity of primate hind limbs, 2) which skeletal features in the hip and knee best correlate with locomotor behavior, and 3) how does phylogeny affect locomotion? The researcher will learn how to post-process micro-CT scans of these specimens, generate three-dimensional models from the scans, and measure functionally informative features of primate hips and knees from the 3-D models. The researcher will also learn how to conduct statistical analyses in R. Hence, the researcher will have the opportunity to learn post-processing techniques and methods of morphometric data collection and analysis. This project could lead to an expanded senior thesis project, a presentation at a professional conference, and/or a publication in a peer-reviewed journal. 


In the event that students are not permitted on campus in the summer, the internship could take place in the fall. There is not a fully remote summer option for this internship. 


Stipend: $2250