Deep-sea seamounts provide benthic habitat in otherwise pelagic realms. Distance, physical oceanography, and life history strategies of seamount fauna combine to make seamounts "islands in the sea." These submerged islands provide model systems to study evolution, endemism, and speciation in the marine environment, just as emergent oceanic islands have been used to study these processes in the terrestrial environment. The investigators will identify and elucidate the extent of co-evolutionary relationships and dispersal processes of four pairs of seamount coral and epifaunal associate species through phylogenetic and phylogeographic studies. The specific objectives of the project are to address whether the New England and Corner Rise Seamounts are promoting the formation of sub-species, as expected for geographically-isolated habitats; whether these seamounts contain coral and associated fauna whose populations are evolving in isolation as opposed to widespread migrations; and whether corals and their associated species are evolving in tandem, and so are being governed by the same dispersal routes and capabilities. The investigators will interpret these data to develop further hypotheses directed at understanding the roles of hydrography, life history, oceanic circulation and co-evolutionary processes as mechanisms of diversification. This research will provide a mechanism to view the processes that shaped (and continue to shape) the migratory rates and evolutionary pathways of marine fauna that ultimately explains modern biogeographic biodiversity patterns in the deep sea. The broader impacts will have application to understanding potential anthropogenic disturbance on deep-sea populations. Seamounts around the world are currently threatened by destructive fishery practices emphasizing the need for greater understanding of the processes affecting uncharacterized species in these habitats. The project will provide postdoctoral training and graduate student support, including the development of graduate-level topics courses within the Joint MIT/WHOI graduate program. The project also includes construction of a faunal guide (and database) of the Northwest Atlantic Seamounts, enriched with high-definition images, ecological and distribution descriptions, bathymetric maps, and evolutionary implications for the diversity of life on the deep-sea seamounts. This compendium will be disseminated to school children, educators, and managers.