Dispersal & speciation
We adress the evolutionary consequences of dispersal, adaptive phenotypic divergence and the constraining effects of gene flow. We investigate parallel evolutionary changes in both multicellular and microbial organisms.
Study organisms include freshwater aquatic isopods (Asellus aquatics), protists (dinoflagellates and raphidophytes) island populations of lizards (genus Podarcis), dragonflies and damselflies (Odonata). We compare phenotypic traits in similar environments and study the genetic independence of populations with similar phenotypic traits using molecular methods (mtDNA and AFLP:s). We are also interested in the general issue of how dispersal might impair local adaptations at range limits, e. g. by causing asymmetric gene flow between core populations in the centre of the species range and marginal populations at the edge of the species range. Our work entails both field experiments across extensive biogeographic scales and the use of high-resolution molecular markers (microsatellites and mtDNA).
As a result of phenotypic divergence, sexual isolation might evolve which in turn might lead to speciation. Geographically separated populations and incipient species might evolve reproductive isolation between each other to reduce the impact of maladaptive gene flow and preserve locally favorable alleles or gene combinations. Important questions here are the ecological correlates of reproductive isolation, the genetic basis of sexual isolation and the role of phenotypic plasticity (e. g. Learning) of mate preferences and sexual isolation.