Two complementary studies will be undertaken in evolutionary physiology. The ultimate goal is to elucidate the bases for differences in organismal performance that may exist among individuals and species, and to understand how and how rapidly capacities for physiological performance may be modified through artificial or natural selection (organic evolution). First, artificial selection experiments with mice will test what proximate physiological and biochemical factors are limiting to the evolution of increased capacities for locomotor performance. At present, cross species comparative data cannot be properly analyzed with standard statistical tests, because species are descended from common ancestors in a hierarchical fashion, and so are neither biologically not statistically independent. A second research thrust will involve using computer simulation techniques to develop and compare alternative statistical methods to correct for phylogenetic non-independence and so provide valid significance tests and parameter estimates for comparative (interspecific) data.
