Meeting Abstract

40.3  Wednesday, Jan. 5  Coevolution of morphology and locomotor performance in Urosaurus ornatus MILES, D B; Ohio University dmiles2@ohio.edu

Species with widespread distributions often exhibit divergence in phenotypic traits. Such variation is attributed to selection imposed by local environmental conditions. Patterns in phenotypic traits that are associated with habitat or other ecological factors often are used to infer an adaptive basis to population differentiation. Although previous studies have examined differences in means among populations, few focus on the covariance among traits. Such a comparison is critical, because population divergence could be due to drift rather than a selective response to local environmental conditions. Furthermore, most analyses focus on morphological traits and do not include functional traits. In this analysis, I compare the variance-covariance among 8 populations of the species Urosaurus ornatus. If population divergence is due to genetic drift, then the among-population covariation should be proportional to the within-population covariation. I estimated the patterns of covariation using 13 morphological traits. I also quantified among-population differentiation in sprint speed and stamina. I compared the pooled phenotypic variance-covariance matrix to the within population-covariation matrix. The analysis found morphological divergence among populations that reflected habitat occupancy rather than constraint. Morphological traits were significantly associated with locomotor performance, but did not show consistent trends with respect to habitat.