9509324 BIELER This award will support collection of DNA sequence data from representative members of "lower heterobranch gastropod (Mollusca: Gastropoda) lineages. These molecular data will be combined with data, some previously collected, from morphological studies involving internal anatomy, ultrastructural features revealed by scanning electron microscopy (SEM), and histological information, as well as external and shell characteristics. These organisms include several "primitive" groups for which the relationships remain unresolved. Elucidation of their relationships will also shed light on the origins of slugs and land snails. The relationships revealed will be of use in trying to understand the fossil record of these animals. This study will contribute to our knowledge of the biodiversity of an amazing phylum of invertebrate animals. Many of the members are marine, but others have made transitions to life on land and in fresh water. Collectively, gastropods or snails, slugs and their relatives are of much importance to human life, as some are an important food source and others harbor parasites of both humans and domestic animals.
