Research in the Davis lab focuses on the evolution of fishes that inhabit the deep sea, as the extreme habitats of this environment have produced fascinating evolutionary events among the 4000 - 6000 species of marine fishes that have invaded this realm (e.g., telescopic eyes, bioluminescence, hermaphroditism). We use phylogenetic hypotheses as frameworks to investigate a breadth of evolutionary questions related to organismal diversity and diversification. Our work focuses on exploring a number of evolutionary topics related to fishes that inhabit the deep sea, including; estimating divergence times, temporal changes in diversification rates, character evolution, correlations between speciation rates and evolutionary adaptations, ecological habitat shifts, and biogeography.