NSF Postdoctoral Fellowship in Biology: Ordered Evolution and Muscle-Specific Specializations of Constriction Behaviors in Snakes

Capano, John, Providence RI

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Constriction in snakes has been long thought to have been an important trait that helped snakes become extremely diverse and widespread. This behavior is quite complex and likely evolved from simpler versions where the snake wrestles its prey instead of coiling. The Fellow will study how this ordered evolution occurred, creating a new framework to understand how complex traits evolve in nature. This multifaceted approach will involve mapping different ‘constriction’ forms on the snake family tree, studying specializations of their muscles, and investigating how these traits are genetically regulated. Moreover, as a first-generation, low-income student, the Fellow will pay forward opportunities he experienced by involving students from a high school, where 90% of the students are from underrepresented groups, in behavioral observations and hands-on experiments with snakes. Novel traits often emerge when ancestral traits gain complexity. However, the mechanisms that iteratively “build” these elaborate traits, fundamental aspects of phenotypic diversity, remain unclear. ‘Constriction’ in snakes exemplifies how physiological and molecular systems intertwine to sustain life. ‘Constriction’ describes hierarchically complex patterns that include (1) fully looping coil constriction; (2) partially encircling hairpin looping; and (3) simple pinioning, similar to wrestling. These are not mutually exclusive, and more complex forms have increased performance despite lacking increases in muscle mass or cross-sectional area (two correlates of force). This suggests ‘constriction’ evolved through an ordered process and involved muscle specialization to produce complexity. This project will categorize constriction behaviors within snakes using phylogenetic comparative methods in order to determine whether ordered evolution occurred. The Fellow will conduct muscle experiments to determine whether complex constrictors have muscles specialized for force production or fatigue resistance. This work will also identify genetic differences between each ‘constriction’ form associated with the variation measured in the former experiments. The Fellow will gain experience with phylogenetic comparative methods, behavioral physiology, and transcriptomics to enhance his future research program and probe what makes snakes so successful. As part of this project, the Fellow will recruit interested students from underrepresented groups at a local high school to assist with experiments that enhance their ability to see themselves as future STEM researchers. 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.