UCLA

Understanding the process that underlie the disparity in species richness across different taxonomic groups is a fundamental question in evolutionary biology. Several difficulties hinder deeper investigation into this field, namely the lack of high quality phylogenetic and phenotypic data to appropriately test competing hypotheses. I use ray-finned fish (class Actinopterygii), which comprise over half of all vertebrate diversity with 30,000 species in 500 families, as a study system to understand the processes that generate biological diversity. In chapter one, I combine previously-published molecular sequence data to generate a new phylogeny of ray-finned fish containing over 11,000 species and time-calibrate it using over 130 fossils. In chapter two, I develop a new method to collect large amounts of morphological data using crowdsourcing. In chapter three, I develop a new method to estimate completely sampled phylogenies using taxonomic information and birth-death-sampling estimators. In chapter four, I present an accessible web resource to distribute phylogenetic data about actinopterygian fishes. In chapter five, I estimate the distribution of exploitation on the fish tree of life, and test whether certain lineages are disproportionately exploited, and whether certain life history or ecological characteristics predispose species to fishing pressure.