Spiny-rayed fishes are one of the most successful radiations of vertebrate animals, with about 17,000 species and astonishing morphological and ecological diversity that includes many culturally and economically important species such as tunas, flounders, seahorses, largemouth bass, and guppies. This diverse group represents one of the last great frontiers to understand vertebrate evolution. In this project, the evolutionary relationships among more than 260 families of these fishes will be studied with several methods of phylogenetic inference using DNA sequence data from 16 protein-coding nuclear genes from specimens of 1,500 species. The phylogenetic trees depicting evolutionary relationships among these groups will be combined with more than 40 fossil calibration points to produce a time-calibrated branching diagram of the evolutionary history of these fishes. This time-calibrated phylogeny and a large data set of functionally important anatomical characteristics of the feeding and locomotor systems from over 1,000 species will then be used to compare the rates of speciation and rates of morphological evolution in lineages that live in the five major habitat types: coral reefs, temperate reefs, near-shore soft bottom, pelagic marine, and freshwater. There is a strong theoretical expectation from previous work that freshwater lineages will show high rates of speciation while coral reefs will show the highest rates of speciation and morphological evolution, but these expectations have never been addressed empirically.
This research will strengthen our understanding of the evolutionary relationships and major evolutionary dynamics of the most successful radiation of vertebrate animals on the earth today. Over 20,000 new gene sequences and the morphological data set from over 1,000 species will be made available to the scientific community. The project will support the development of three postdoctoral scholars and has a major undergraduate training program.
