Research Starter Grant: The Morphological Consequences of Competition in Plethodon Salamanders

Iowa State University, Ames IA

Investigators

Abstract

Competition among closely related species is thought to be an important factor driving species distributions. Though competition among salamanders in the genus Plethodon appears to be common, the consequences of competition on morphology are less well understood. In this project, hypotheses about morphological change will be tested in two well-characterized species pairs. Several methods will be used to quantify morphology, including linear distance measurements and landmark-based geometric morphometric methods. For P. jordani and P. teyahalee, it is hypothesized that morphological differences are more extreme in the Smoky Mountains than in the Balsam Mountains. This hypothesis is based on knowledge of ecological and behavioral interactions of these species in the two mountain ranges. For P. cinereus and P. shenandoah, it is hypothesized that an extinct population of P. shenandoah and a nearby population of P. cinereus are more morphologically similar than populations in other regions where both species coexist. This hypothesis is based on knowledge of behavioral and aggressive interactions. Results from this project will help us understand how interspecific competition affects morphological variability in Plethodon, which has important consequences for how organisms interact with their environment. On a larger scale, results from this project will provide a better understanding of the relative importance of competition as a driving force behind community assemblages, and help us understand the influence of competition on the geographic distribution of organisms.