BEGOVIC, Emina; LINDBERG, David R.; University of California, Berkeley; University of California, Berkeley: Genetic Signatures Of Dispersal: Separating Life History From Ecology And Phylogeny

The ecological effects of larval dispersal capabilities in marine invertebrate life histories have long been recognized, but their implications for evolutionary events such as speciation, extinction, and genetic population structure, have only recently been experimentally studied using molecular data. In order to address the question of how larval dispersal or lack thereof affects population structure of near shore marine taxa with diverse life histories, we sampled the cytochrome oxidase I gene (COI) from three North Pacific patellogastropod species co-occurring on coralline substrates in the nearshore subtidal throughout the Aleutian Islands, Alaska. Tectura testudinalis, Erginus sybaritica and Erginus apicina all feed on coralline algae, however T. testudinalis is a broadcast spawner while E. sybaritica and E. apicina are brooders. We hypothesized that these differences in reproductive strategy would be reflected in each species� genetic population structure. Taxa were chosen based upon their similar biogeographic range, presumed ecological similarities and phylogenetic position. COI data indicate that population structure is directly affected by reproductive life history strategies when the ecological context of the study organisms is held constant and phylogenetic effects are accounted for, giving us a better measure of dispersal�s contribution to population structure. This type of natural control has not been achieved in previous comparative phylogeographic studies on marine gastropods.