Most researchers working with living systems use relatively simple organisms to understand complicated processes. Students of human disease, for instance, use rats and mice; geneticists use yeast cells and fruit flies; and developmental researchers use roundworms. As studies of ecology and evolution become increasingly sophisticated, some scientists have suggested that those fields should also establish model systems. A colloquium to address the question will be held Oct. 16-18 at the UC Davis Bodega Marine Laboratory at Bodega Bay, Calif. Scientists from North America and Europe will discuss species competition for resources, relationships between predators and prey, and how communities of species co-exist. They will also consider whether particular communities or systems of species could serve as representatives for all types of ecological and evolutionary studies. The meeting, "The Role of Model Systems in Ecological and Evolutionary Research," is the culmination of the Bodega Field Conference, a federally funded, five-year program of research and workshops on the California coastal prairie community.