Local selective sweeps in Drosophila melanogaster

The identification of local selective sweeps by analyzing variability pattern at neutral markers has recently become a very popular approach in population genetics. In D. melanogaster several recent studies identified a number of genomic regions that deviate from neutral expectations and are thus good candidates for a putatively selected region. Nevertheless, is has also become clear that certain demographic events could create a signature that is very similar to a selective sweep. This proposal takes advantage of population structure in non-African populations to identify sweep regions that are specific to local populations/continents. In addition to the analysis of candidate regions in a biogeographic setting, this proposal aims for the characterization of admixture between D. melanogaster populations. Previous work provided some evidence for a chromosome specific admixture pattern. Based on these results, a genome wide survey for chromosome specific admixture in D. melanogaster will be carried out and the driving evolutionary forces will be characterized.

This project spanned a very broad range of questions, all related to population structure and selection in Drosophila. The focus was on the establishment of using next generation sequencing of DNA pools as a tool in evolutionary genetics. In the project several software tools were developed for the analysis of Pool-Seq data, most of the tools are freely available from the google code webpage. Using these tools we characterized natural populations and experimental populations exposed to novel environments.