This action funds a Postdoctoral Research Fellowship in Biosciences Related to the Environment for 1995. This program of fellowships to individuals provides opportunities for Fellows to gain additional scientific training beyond the doctoral degree and to pursue innovative and imaginative research into the fundamental mechanisms underlying the interactions between organisms and their environment at the molecular, cellular, organismal, population, community, and/or ecosystem level in any area of biology supported by the Directorate for Biological Sciences of the National Science Foundation. This program is designed to enable selected scientists early in their careers to improve and expand their research skills, to direct their research efforts across traditional disciplinary lines, and to avail themselves of unique research resources and facilitites, including foreign lmcations. The research and training plan supported by this fellowship is entitled: An experimental study of the effect of metapopulation structure on parasite-host population dynamics.