This project continues its genetic studies of deep-sea organismsfrom hydrothermal vent and cold-water sulfide/methane seeps. The objectives of the study are: 1) to obtain estimates of gene flow among populations living in hydrothermal vent fields along ridge crests throughout the world's oceans; and 2) to define phylogenetic relationships among hot-vent species and similar fauna living in cold-vent sulfide/methane seeps. During the past 30 months, frozen samples of more than 100 species have been collected during submersible dives to over 25 distinct vent and seep areas throughout the world. Additional dives are plan at sites from which adequate samples are not available. Genetic data are obtained from examination of allozymes, mitochrondrial (mt) DNA, anonymous single-copy nuclear (scn) DNA, and direct sequencing of PCR amplified genes. This integrated genetic approach has already revealed much higher species diversity in these deep-sea habitats than was previously known. Whether the vent organisms of a family constitute a monophyletic group, whether they had polyphyletic origins from related seep fauna, or vice versa remains to be discovered. Ongoing genetic studies are providing a comprehensive picture of relationships within and between the dominant species living in these unusual abyssal environments.
