Date of Award
Doctor of Philosophy
Ecology, Evolution, and Organismal Biology
Ecology and Evolutionary Biology
Dean C Adams
Understanding interspecies patterns and the mechanisms that generated them is key in macroevolutionary theory. Often, these patterns can be attributed to selection affecting groups of lineages in different manners. Under the ecomorphological paradigm, we investigated the macroevolution of organismal morphology and performance and patterns of sexual dimorphism in anurans, as well as the likely selective factors that could have resulted in the phenotypic diversification of anurans. Using phylogenetic comparative methods and by developing new methods to approximate jumping performance based solely on morphology, we showed how we may use preserved specimens to study the macroevolution of jumping performance in anurans. These methods for approximating jumping likely apply to other jumping vertebrates as well. Next, we determined the extent to which sexual dimorphism in jumping performance in relation to microhabitat was driven by sexual size dimorphism and individual male and female patterns of jumping performance and morphology. This resulted in the finding that macroevolutionary patterns of sexual dimorphism in jumping velocity in relation to habitat use are primarily driven by female differentiation in particular habitats but only partly associated with differences in leg skeletal and muscular morphology. These findings suggested that natural and sexual selection across microhabitats, possibly associated with many-to-one mapping, is key in explaining the history of phenotypic and ecological diversification in anurans. Additionally, this study identified that sexual dimorphism in size and muscle volume are of similar magnitude across anurans. Finally, we investigated whether sexual dimorphism in jumping performance displayed evolutionary allometry. We also tested whether sexual dimorphism in the morphological traits underlying our estimates of jumping performance displayed evolutionary allometry. Our study revealed that species exhibiting extreme jumping performance are associated with decreased levels of sexual dimorphism in jumping performance. Leg morphology showed the same pattern. Thus, we argue that natural selection acting on male jumping performance explains the patterns of evolutionary allometry. Specifically, the result of natural selection for increased jumping performance seems to be larger muscle volumes in males relative to females. Overall, this dissertation showed that males and females can display distinct evolutionary histories with differential selection on jumping performance between the sexes and across species playing key roles in the evolution of anurans.
Bryan Hernandez Juarez
Juarez, Bryan Hernandez, "Macroevolution of jumping performance, sexual dimorphism, and habitat in Anura" (2021). Graduate Theses and Dissertations. 18521.
Available for download on Saturday, December 04, 2021