Gene Flow and Species Diversity in Deep-Sea Hydothermal Vent Communities

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9633131 Vrijenhoek Funding is requested for genetic studies of organisms associated with mid-ocean ridge systems and cognate environments in the deep sea. The primary objectives of the study are: (1) to examine spatial and temporal effects of fast- versus slow-spreading ridge axes on intraspecific phylogeography, patterns of dispersal, and rates of gene flow; and (2) to continue our studies of evolutionary relationships among organisms from deep-sea hydrothermal vents and cognate communities in other reducing environments (e.g., cold-water sulfide/methane seeps, whale fall, etc.). As a result of previous oceanic expeditions, an extensive collection of frozen specimens from fast-spreading ridge systems in the eastern Pacific already exists at Rutgers University. These organisms have been the focus of ongoing studies of gene flow and patterns of dispersal. To test the hypothesis that the spreading rate of a ridge system plays a dominant role in shaping ecological and evolutionary processes, comparative studies will be conducted with organisms from a slow-spreading system (the Mid-Atlantic Ridge) and a super fast-spreading system (the southern East Pacific Rise). Additionally, ongoing molecular systematic studies of vent and seep bivalve mollusks will be continued, as many new populations and new morphospecies have been described during the last several years. Some of the vesicomyid clam species, in particular, appear to wide distributions that span oceanic basins and terrestrial barriers to dispersal. As the goal of these studies is to obtain multi-locus genealogical information for population level and phylogenetic analyses, a variety of genetic techniques are employ ed (e.g., allozymes, restriction analysis of mitochondrial DNA and anonymous nuclear DNAs, and sequencing of PCR amplified genes). Partial use of an automated sequencing facility is available to the principal investigators. These proposed studies will provide a comprehensive picture of ecological, geological, and evolutionary processes affecting the dominant species that live in these unusual abyssal environments. Present research already has produced molecular markers that are of broad use for students of invertebrate systematics and population genetics. The biodiversity aspects of this research have been recognized with a supplementary award (NIH) to facilitate materials and technology transfer to parties interested in marine natural products discovery.