MCELROY, EJ*; REILLY, SM; Ohio University; Ohio University: The evolutionary relationship between foraging mode and locomotor functional morphology in lizards

Foraging mode has impacted many aspects of lizard biology. Locomotion is centrally important to foraging and therefore the morphology and function of the locomotor system should be a strong correlate of foraging mode phenotype. Here we present an initial assessment of the evolutionary patterns between foraging mode and locomotor functional morphology among lizards. We collected whole-body mechanics, simple kinematics, and limb-segmental morphology data on 14 species spanning a phylogenetically diverse 10 families. A racetrack with incorporated force plate was synchronized with high-speed video to quantify whole-body mechanics and simple kinematics. We used multivariate and phylogenetic analyses to understand the relationships between morphology, function, and the evolution of foraging behavior. Sit-and-wait foragers appear to have locomotor functions that facilitate fast locomotion (i.e. trotting gait, running mechanics, low percent recovery). Wider foragers appear to retain the same locomotor functions at fast velocities. However, the evolution of wider foraging strategies is characterized by a reduction in moving velocity to facilitate prey recognition and capture. At slower velocities, wider foragers add a new suite of locomotor functions (i.e. lateral sequence diagonal couplets gait, walking mechanics, and substantial energy recover). These novel locomotor functions are thought to facilitate sustained slow velocity locomotion via improved energy economy and stabilization. Phylogenetically sit-and-wait foraging is hypothesized to be the ancestral phenotype with wider foraging behaviors evolving multiple independent times. Our data support this idea: each time wider foraging evolves, the locomotor system evolves in a unique and independent way.