Stephan Peischl has a broad interest in evolutionary biology and population genetics. His main areas of interest are the interaction of ecology and population genetics, the theory of speciation, and adaptation to (spatially and/or temporally) changing environments. Coming from a mathematical background, his work is mainly theoretical: He develop and analyze mathematical models of evolutionary processes. He has been working on a variety of topics including the evolution of genetic architecture under disruptive selection, the evolution of assortative mating in sympatry, the maintenance of polymorphism in migration-selection models, coalescent models with non-standard patterns of recombination, and stochastic models for the establishment of new mutations in temporarily or spatially changing environments.
The interaction of recombination with selective and non-selective processes impacts both functional and neutral diversity across the genome where a positive correlation between genetic diversity and recombination is generally expected. Contrastingly, a possible transition from background selection (BGS) to associative overdominance (AOD) at sites tightly linked to a locus with recessive deleterious mutations may lead to a switch from reducing to increasing diversity in genomic regions of very low recombination. Here we study the prevalence of AOD and its impact on genomic diversity in a genomic context where multiple linked recessive loci co-segregate in regions of low recombination. We investigate the evolutionary dynamics of multi-locus AOD through a combination of simulation and mathematical modelling that allows us to identify empirical signatures of AOD in humans.