9408089 ROSENBERG This project will utilize information from internal anatomy and allozyme electrophoresis to determine relationships among approximately 25 species of land snails in a genus which occurs on major islands in the West Indies. These very interesting snails are terrestrial but their closest relatives have an amphibian existence. The project will investigate whether this transition to land-dwelling has been made once, with the snails then dispersing to other islands, or whether there have been, instead, multiple land invasions with each island having been colonized separately from an amphibious ancestor. %%% This project will contribute to our knowledge of biodiversity in these restricted island faunas. The snails are an excellent model system for investigating the transition to an existence on land and the marked changes, especially in the respiratory system, that must occur with such a major habitat shift. Information about the geologic history of the islands should also emerge as patterns in relationships of the snails should reflect relationships or relative times of origin for the islands. ***
