Meeting Abstract
Superior locomotor performance is associated with advantages in terms of male combat success, survival, and fitness in a variety of organisms. In humans, investment in increased performance via the exercise response is also associated with numerous health benefits, such as decreased incidences of metabolic syndrome, cardiovascular disease, obesity, and diabetes, and aerobic capacity is considered to be an important predictor of longevity. One of the most striking aspects of exercise physiology is how similar the response to exercise is across vertebrate animals, suggesting that the response to exercise is both ancient and adaptive. However, no studies have tested whether non-human animals that invest in increased athletic performance through exercise realize a fitness advantage in nature. Previous work with green anole lizards showed that they respond to different forms of exercise training, and that enhanced performance results in tradeoffs in other systems, such as reproduction and immnuocompetence. We released sprint-trained, endurance-trained, and untrained-control male and female green anole lizards into isolated, urban islands in New Orleans, LA, USA and monitored their survival. We predicted that training would enhance survival during the active season, but that the associated maintenance costs of training would decrease survival overwinter compared to controls. We found that sedentary controls realized a significant survivorship advantage over all time periods compared to trained lizards. Our results suggest that locomotor capacity is currently optimized to maximize survival in green anoles, and that forcing additional investment in performance moves them into a suboptimal phenotypic space relative to their current environmental demands.
