SICB 2015: Physiological Correlates of Individual Activity Rates

Jamal Murray. Photo from Johnson Lab website.

Activity is where the rubber meets the road in the interaction between organisms and their physical and social environments: in order to acquire energy, attract mates, and produce offspring you have to get up and move around. But what dictates how much activity an individual will engage in? We know a fair amount about what causes organisms to be more or less active, with temperature a particularly important one for ectotherms like anoles. Nonetheless, the physiological mechanisms that underlie activity variation are less well understood. Jamal Murray, an undergraduate in Michele Johnson’s lab, presented a poster at SICB that begins to address this question with the Puerto Rican Anolis stratulus. He put lizards into an enclosure with grids marked on all sides, and measured activity rates as the number of times individuals moved from one grid to another. Afterward, he measured blood glucose levels and found that individuals with higher glucose levels were more active. This suggests a proximate physiological mechanism driving differences in activity rates among individuals and, potentially, populations and species.