Meeting Abstract

117.6  Tuesday, Jan. 7 11:30  The Evolution of Muscle Physiology and Social Behavior in Caribbean Anolis Lizards JOHNSON, MA; Trinity University mjohnso9@trinity.edu

Lizards in genus Anolis (anoles) are a model system in studies of evolution, ecology, and behavior, yet relatively little is known regarding the diversity of behavioral mechanisms in this group. While the mechanisms associated with social display and copulatory behaviors have been described in the green anole (A. carolinensis), we do not yet understand how the physiological and neuroendocrine traits that underlie these behaviors vary across the genus. Using 6-9 species, I used phylogenetically-informed comparative analyses to determine whether the frequency of muscle use in display or copulation is associated with the size of the muscle fibers, the fiber type composition of the muscles, and the expression of androgen receptors in the muscles. Results of these studies reveal that the size of the muscle fibers controlling push-up displays and copulation behaviors are associated with the frequency of their use; but in the muscles controlling dewlap (i.e., throat fan) extensions, expression of androgen receptors is associated with the frequency of dewlap use. Comparing these results to studies of intraspecific variation in the green anole demonstrates that the evolution of behavioral mechanisms across the genus may follow multiple trajectories.