Meeting Abstract
Why do organisms with similar ecologies often have similar morphology? Evolution of morphology usually results from selection on functional performance, so to answer this question we need to understand the relationship between form and function. Furthermore, within a given group of organisms (e.g. frogs), selection may favor high performance in general behaviors shared by many species (e.g. jumping) and also high performance in environment-specific behaviors (e.g. swimming, burrowing) in only a subset. Thus, does the morphology of a species that uses multiple environments reflect performance tradeoffs across those environments? Or does functional redundancy (many-to-one mapping) permit morphology that produces high performance in multiple behaviors? Here, we study the relationship between morphology and performance in 44 species of anurans (frogs and toads) that inhabit different microhabitats (i.e. different ecomorphs) and examine how that relationship may explain their distinctive morphology. We first test whether anuran ecomorphs differ in jumping and swimming performance and leg morphology. We then estimate the relationships among relative leg length, relative leg muscle mass, and performance in jumping and swimming. Finally, we combine these results to examine whether functional redundancy explains the morphology of the different ecomorphs. We find that long legs and muscular legs both increase jumping and swimming performance, but their relative importance for the two behaviors dictates which form (especially long or especially muscular legs) best describes anurans in different microhabitats. Thus, functional redundancy, rather than performance tradeoffs, better explains the leg morphology of frogs in different microhabitats.
