Meeting Abstract

7.3  Saturday, Jan. 4 08:30  Body Size Evolution and Species Diversity in North American Minnows MARTIN, S. D.*; BONETT, R. M.; Univ. of Tulsa; Univ. of Tulsa samuel-martin@utulsa.edu

Body size is one of the most important traits influencing an organism’s ecology and is often a major axis of evolutionary change. Among freshwater fishes, body size may influence patterns of biogeography and macroevolution. Smaller fishes can occupy smaller streams, are generally poorer dispersers, and are thus more likely to become isolated among drainages. Since isolation can promote speciation through allopatric divergence, small fishes may have higher diversity in a region. We tested for a relationship between body size and diversity in a highly speciose endemic clade of North American minnows (Leuciscinae), which exhibit diverse body sizes. We developed a time calibrated, species level phylogeny based on 7 mitochondrial genes and 12 nuclear genes. We then used this phylogeny to reconstruct ancestral body sizes, compare rates of size evolution among subclades, and examine whether body size has influenced the species richness of North American minnows.