Meeting Abstract
Natural selection acts on phenotypic variation within a population. Phenotypes are highly integrated, so selection for or against a trait can indirectly select for or against integrated traits. Integration of physiological and morphological traits results in and constrains performance traits in animals. Since performance forms an interface between the animal and its environment, it is ecologically relevant and can be under direct selection. Knowing how the physiology and morphology of an animal integrate to form a performance trait is critical to understand how selection works in that animal. Investment in one performance trait can lead to decreased performance elsewhere, a tradeoff. Variation among these traits can provide insight into how selection has worked in the past. Phenotypic variation exists at multiple levels of organization, and studying variation at multiple levels (within organisms, within populations, between populations) can reveal relationships which could be overlooked if only analyzed at one of these levels. For this study, we captured prairie lizards (Sceloporus consobrinus) from sites in central Arkansas and southern Missouri. We took repeated laboratory measurements of morphological, physiological, and performance traits associated with locomotion on each animal to account for variation both within and among the lizards. We analyzed the data using multivariate mixed-effects models, which allowed us to identify any correlations or tradeoffs that exist between traits both within and among individuals and whether relationships that existed within individuals were masked when studied in the population. This study will lay the groundwork for future research on how these traits are actively selected in the field.
