Large-scale patterns in genetic variation, gene flow and differentiation in five species of European Coenagrionid damselfly provide mixed support for the central-marginal hypothesis.
(English)In: EcographyArticle in journal (Refereed) In press
Recently, an increased effort has been directed towards understanding the distribution of genetic variation within andbetween populations, particularly at central and marginal areas of a species’ distribution. Much of this research is centredon the central-marginal hypothesis, which posits that populations at range margins are sparse, small and geneticallydiminished compared to those at the centre of a species’ distribution range. We tested predictions derived from the centralmarginalhypothesis for the distribution of genetic variation and population differentiation in five European Coenagrioniddamselfly species. We screened genetic variation (microsatellites) in populations sampled in the centre and margins of thespecies’ latitudinal ranges, assessed genetic diversity (HS) in the populations and the distribution of this genetic diversitybetween populations (FST). We further assessed genetic substructure and migration with Bayesian assignment methods,and tested for significant associations between genetic substructure and bioclimatic and spatial (altitude and latitude)variables, using general linearized models. We found no general adherence to the central-marginal hypothesis; insteadwe found that other factors such as historical or current ecological factors often better explain the patterns uncovered."is was illustrated in Coenagrion mercuriale whose colonisation history and behaviour most likely led to the observationof a high genetic diversity in the south and lower genetic diversity with increasing latitude, and in C. armatum and C. pulchellum whose patterns of low genetic diversity coupled with the weakest genetic differentiation at one of their rangemargins suggested, respectively, possible range shifts and recent, strong selection pressure.
Genetics Evolutionary Biology Ecology
IdentifiersURN: urn:nbn:se:umu:diva-62268OAI: oai:DiVA.org:umu-62268DiVA: diva2:576931