Doctoral Dissertation Research: The Evolution of Locomotor Specializations in the Context of Adaptive Plasticity

Plasticity refers to alterations to an organism’s behavior, anatomy, or physiology in response to environmental conditions and can lead to the evolution of novel features and behaviors. Many hypotheses regarding the origin of hominin bipedalism (walking on two legs), one of the earliest defining features of the human lineage, involve a phase of plasticity. This doctoral dissertation project examines the role of plasticity in primate locomotor specializations to advance knowledge about human bipedalism by placing humans within a broader primate context. This research highlights the potential early stages of the evolution of bipedalism, and findings from this research can inform future interpretations of the human fossil record. This research supports STEM training and mentorship of underrepresented high school and undergraduate students. The project has two main objectives. The first objective is to investigate the relationship between plasticity and evolvability of limb bones in reference to the locomotor repertoire of 15 primate species. The investigators collect and analyze 3D landmark data from limb bones across humans, apes, and monkeys with varying degrees of specialization. For the second objective, a robotic simulation approach is used to model how plasticity of locomotor repertoire can result in the origin of novel behaviors, as well as impact fitness and extinction risk. Robotic models based on six modern primate species and four hominin fossil species are run through a series of simulated environments. The algorithm for these simulations links two different forms of robotic modeling – evolutionary and developmental – which can be applied to other instances of adaptive plasticity in primates and made available for other researchers to use. 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.