9424091 Berrigan The International Junior Investigator and Postdoctoral Fellows Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twelve-month postdoctoral research visit by Dr. David A. Berrigan to work with Dr. Ary A. Hoffmann at La Trobe University in Australia. Acclimation is an important physiological adaptation to environmental variability, which occurs in response to a variety of environmental stresses such as temperature, desiccation and salinity. Dr. Berrigan proposes three approaches to assess the distribution of acclimation responses and to measure their costs and benefits. First, he will survey a number of Australian fruit flies, (species Drosophila) for acclimation responses to heat and cold. Second, he plans to estimate the cost of acclimation to heat or cold using a combination of life history and physiological assays. Third, he will experimentally distinguish between injury from exposure to temperature extremes and the costs of acclimation using comparative studies of species with and without acclimation responses. The goal is to use these measurements to develop models for the evolution of acclimation responses to temperature. ***
