Abstracts - Deutsche Zoologische Gesellschaft

46 Evolutionary Biology SymposiumO EB.16 (Mo) - DEPhylogeography of the southern skua complex – rapid colonisation of the southernhemisphere during a glacial period and reticulate evolutionMarkus Ritz, Craig Millar, Gary D. Miller, Richard A. Phillips, Peter Ryan, Viviane Sternkopf,Dorit Liebers-Helbig, Hans-Ulrich PeterInstitute of Ecology, Friedrich-Schiller-Universität JenaWhilst we have now a good understanding how past glaciation influenced species at the northernhemisphere, our knowledge of patterns and modes of speciation is far more limited for the southernhemisphere. We provide mtDNA based data on the phylogeography of a circumpolar distributedsouthern hemisphere seabird group – the southern skua complex (Catharacta spp.). Diversificationof southern skuas dates between 210,000 yBP and 150,000 yBP and coincides with a glacial spanning230,000 – 140,000 yBP. Skuas most likely first inhabited the Antarctic continent, in the courseof global cooling and increasing glaciation spread to the sub-antarctic islands and Tristan da Cunhaand finally colonised Patagonia and the Falkland Islands at the glacial maximum. Despite significantdifferences between taxa most populations still exchange genes with neighbouring populations ofother taxa and speciation is incomplete.O EB.17 (Mo) - DEDiversity and variation of mandible shape in wild house mice and their close relativesLouis Boell, Diethard TautzEvolutionsgenetik, Max-Planck-Institut für Evolutionsbiologie, PlönA prerequisite to the study of evolutionary diversification of morphology is knowledge about naturalvariation. Our study system is the mandible of house mice. Variation in mandible shape is exploredusing Geometric morphometrics in wild and laboratory populations, with a focus on Mus musculusdomesticus but also including M. m. musculus, and the closely related M. spretus and M. macedonicus.First results include: - within the subspecies M. m. domesticus, there is clear but small divergenceamong populations from different geographical areas. - within the European Mus complex,divergence is not distributed according to taxonomic distance. - Phenotypic plasticity appears to benot very influential on phenotypic divergence. - Outbred populations are more variable under laboratoryconditions than inbred strains, suggesting the presence of important genetic standing variation.This broad survey will allow us to ask precise questions about the distribution of subtle morphologicalvariation and to choose study populations for investigations on the quantitative genetics of shapedifferences. Using In-vivo-microCT, an artificial selection experiment on shape in a biologicallymeaningful direction in shape space will be performed and used for hitchhiking mapping. Functionalstudies using cinematoradiography are also planned. The combination of the resulting morphologicaland genetic data should provide a powerful basis for further investigations of morphologicaldiversification.