Meeting Abstract
Body size features prominently in nearly every aspect of organism’s biology, including several fitness-related parameters such as fecundity, mating success, energy budget, and life span. Thus, explorations of macroevolutionary trends associated with the tempo and mode of size-evolution are important in understanding the diversity of size in ray-finned fishes. Here we use body length data from 1,400 species of extant actinopterygians and the most current and expansive multi-locus phylogeny for the group to evaluate a multitude of models of log-transformed body-length evolution. We found that the tempo of size evolution in ray-finned fishes is explain best by an Ornstein-Uhlenbeck (OU) process, thereby suggesting that size evolves toward a phenotypic optimal value. In addition, to assess which ecological parameters may contribute to size diversity, we gathered distribution and habitat data for all of our included species. Using phylogenetic generalized least squares analysis under both OU and Brownian motion error models, we found that depth and ecoregion explain 60% of the variation in body length. Together, these results suggest that the evolution of body size is influenced by the ecophysiological constraints of habitat preference.
