Population genetics in an ecological context

The aim with the present project is to provide a link between population genetics and ecology. The project has both a theoretical and a empirical part. In the theoretical part we will focus on development of models for random genetic drift that can be use d under natural conditions. This models will include age-structure, density dependence and fluctuating environments and can be used to derive useful metrics such as the population size necessary to obtain a certain expected heterozygosity or the probabili ty of extinction of a rare allele. They will also form null models for testing hypotheses about the influence of selection on the genetic compostion of natural populations. In the empirical part, we will first use the theoretical framework to examine in c arefully selected study systems ranging from house sparrows to long-lived ungulates which factors that most strongly influence the rate of genetic drift in those populations. We will then extend this study by using a large data base of long-term populatio n dynamical studies of birds to an examination of whether interspecific variation in genetic drift can be predicted from ecological variables or knowledge of life hsitory characteristics. A central focus of the project will also be to improve our understa nding of evolutionary respones in quantitative characters to selection. We will use modern statistical techniques to develop methods that improve the precision in the estimates of crucial genetical paramters that are extremely difficult to estimate under natural conditions. We will then experimentally examine using artificial selection whether we can predict from our theoretical framework the responses in quantitative characters to a given selection regime