PhD Proposal by Cassie Shriver

Quantitative Biosciences Thesis Proposal

Cassie Shriver

School of Biological Sciences
Advisors: Dr. Young-Hui Chang (School of Biological Sciences), Dr. David Hu (Schools of Biological Sciences, Mechanical Engineering)

Open to the Community

Mechanics and Morphology of Mammalian Climbing with Applications for Conservation

Monday, September 18, 2023, at 1:30pm

In Person Location: IBB 1128 (Suddath Seminar Room)

Zoom Link: https://gatech.zoom.us/j/93662909985

Committee Members:

Dr. Greg Sawicki (Schools of Biological Sciences, Mechanical Engineering)

Dr. Craig McGowan (Keck School of Medicine, University of Southern California)

Abstract:

While recent work has examined climbing via van der Waals forces and capillary adhesion, these methods of attachment are often restricted to non-mammalian species less than 500 grams. Larger animals are subject to scaling constraints that make it harder for area-dependent functions like muscle force generation to accommodate volume-dependent functions like gravitational effects. Even amongst the studies for mammals, however, many are focused on primates, which take advantage of highly specialized opposable thumbs, elongated digits, and/or prehensile tails. Principles explaining how non-primate mammals climb remain tremendously understudied.

This proposal will begin to address this gap through the lens of locomotor constraints in climbing. First, I will apply seminal terrestrial gait kinematics work to mammalian climbing to quantify the kinematic parameter space used by climbers. Second, I will examine scaling relationships of claw parameters to determine tradeoffs in grip and fragility in the context of providing suitable adhesion to the climbing surface. Third, I will propose analyzing the economy, or cost of transport, for different climbing strategies for animals of different masses to discern if there is an optimal speed to balance the cost of supporting body weight with the cost of doing mechanical work to actively climb. The overall goal of this proposal is to develop a predictive model for mammalian climbing and strategy informed by these understandings of kinematics, morphology, and energetics.

Finally, this research would not be possible without collaborations with zoological and wildlife institutions. Aside from being difficult to study in traditional laboratory settings, many mammalian climbers are threatened, endangered, or lack sufficient data to determine conservation status. I propose capitalizing on these interdisciplinary collaborations to promote conservation efforts locally and in the wild through research, education, and outreach.