Michael S. Taylor
Southeast Missouri State University
My research on the genus Elacatinus focuses on the identification of genetic and ecological processes that may have promoted the evolution of species richness in this genus. Possible mechanisms that may have governed reproductive isolation and speciation may be identified though the use comparative phylogenetic and phylogeographic analyses. I apply these analyses to mitochondrial and nuclear markers at both the species and the population level.
To date, I have demonstrated that the diversity of these gobies resulted from a combination of 1) extremely limited gene flow among island populations, despite high larval dispersal potential, 2) regional subdivision of the Caribbean Sea by little recognized biogeographic barriers, and 3) rapid ecological differentiation of sister taxa by coloration. Because sister species of Elacatinus differ by color, I hypothesized that variation in genes related to color vision (opsins) may correspond to color variation in Elacatinus. I isolated and sequenced the two opsin genes related to color vision, as well as one related to vision in dim light. Although the sequence variation of the opsin genes does not correspond to color changes in Elacatinus, my ongoing research suggests that observed genetic variation in opsins may correspond to ecological differentiation between some sister species.
The genus Bollmannia contains 13 described species, with nine species in the Pacific Ocean and four in the Atlantic. The division between the oceans suggests that closure of the Isthmus of Panama approximately three million years ago may have generated one or more evolutionary lineages associated with each ocean basin. Phylogenetic analyses of mitochondrial cytochrome b suggests at least two splits are associated with closure of the Isthmus, but we still lack some species.
Bollmannia boqueronensis photo copyright © James Van Tassell with gobiidae.com.