9623796 Grosberg When a mechanism evolves that prevents the exchange of genes between previously interbreeding populations, both populations gain the potential for independent evolutionary divergence. This process, referred to as reproductive isolation or biological speciation, ensures the evolutionary independence of a population, providing an opportunity for further morphological, physiological, and behavioral divergence. In the research funded by this award a multidisciplinary research plan will be carried out to integrate data from mating studies, the fossil record, and a highly resolved DNA-based phylogeny of populations to analyze the evolution of reproductive isolation between two diverging species of predatory marine snails, Nucella emarginata 'northern' and N. emarginata 'southern'. Findings will make possible an understanding of the process of speciation within one of the most common taxa of intertidal snails found on the rocky shores of western North America. Ultimately, present patterns of biological diversity are directly influenced by the rate at which speciation occurs in nature. Reconstructing the historical patterns of variation before, during, and after the evolution of reproductive isolation provides insight into the processes which drive the evolution of isolating mechanisms and the radiation of species. Such knowledge can directly enhance efforts to conserve biodiversity in marine systems.
