INVESTIGATING THE MICROEVOLUTIONARY PROCESSES THAT PROMOTE AND MAINTAIN BIODIVERSITY AND TRAIT NOVELTY

Abstract

Gene flow, mutation, selection, and genetic drift influence patterns of speciation, adaptation, and biodiversity. In the age of genomics, we have been increasingly able to understand the interplay between these microevolutionary processes at the genomic level, and their link to the phenotype and the environment. This, in turn, has provided clarity to the patterns of diversity and biological innovation that these processes generate. My dissertation examines how these microevolutionary processes have influenced patterns of diversity and the evolution of a novel trait in true toads (Anura: Bufonidae). First, I explore what processes (gene flow, incomplete lineage sorting, poor taxonomic resolution) have caused patterns of mitonuclear discordance in a closely related species complex of Mesoamerican toads. I then investigate how this pattern of discordance may have hampered the taxonomic resolution of the species in this complex. Finally, I use North American bufonids to explore potential gene and pathway involvement in defensive toxin synthesis.