Abstract DBI-9803908 Amy L. Denton This action funds an NSF/Alfred P. Sloan Postdoctoral Research Fellowship in Molecular Evolution for 1998. These fellowships support studies involving the theoretical, comparative, computational, and/or experimental analyses of biological patterns and processes at the molecular level within the framework of organismic evolutionary questions. Each fellowship supports a research and training plan to be carried out in a sponsoring laboratory. The research and training plan for this fellowship is entitled the history of natural selection and other evolutionary processes in the chalcone synthase genes of two grass species. This study uses coalescent theory to examine evolution at the chalcone synthase (Chs) loci in maize and pearl millet. The relative importance of effective population size, mutation, recombination and selection is being evaluated through statistical analyses of Chs gene genealogies. The primary goal of the research is to detect the influence of selection and explore the historical forces that have governed molecular diversity in a major plant biosynthetic pathway.