Das Projekt "Shedding light on biological diversity: facilitators and constraints of adaption to anthropogenic environmental changes" wird vom Umweltbundesamt gefördert und von Eawag - Das Wasserforschungsinstitut des ETH-Bereichs durchgeführt. Natural populations are increasingly exposed to extreme environmental changes as a result of human activities. These changes threaten the existence of populations and cause strong natural selection at short time-scales. In the long term, the persistence of populations is determined by their capacity to respond to this selection via genetic adaptation. It is therefore crucial to understand how evolutionary processes influence the ability of populations to cope with the ongoing environmental changes. This project focuses on studying two major factors that influence the ability of populations to adapt to rapid environmental change: gene flow (movement of genes resulting from dispersal of individuals) and maternal effects (the effects of a mother's traits that, in addition to offspring's own genes, affect offspring performance), both of which have the potential to either impede or speed up adaptation. On this vein, the proposed research focuses in particular on understanding how gene flow and maternal effects affect the ability of populations to adapt to environmental changes. The main part of the research will be conducted on Swedish populations of the moor frog (Rana arvalis) that inhabit areas affected to different extents by human-induced acidification. The main questions to be targeted are i) to what extent is the level of local adaptation to acidification explained by variation in the extent of gene flow or variation in the strength of selection among populations, ii) how wide-spread are maternal effects as adaptations and iii) how is maternally determined local adaptation maintained in the face of gene flow? Because experimental manipulations are not possible in these natural populations, related questions will in parallel be addressed in a pilot study on laboratory populations of Daphnia. Here the main questions to be targeted are i) under which conditions does gene flow have positive vs. negative effects on adaptation to novel environments and ii) how do maternal effects influence the ability to respond genetically to rapid environmental changes? Different complementary approaches will be used in the different subprojects to allow rigorous inferences and predictions. The main methods to be used include large-scale geographic sampling (for environmental, molecular genetic, and phenotypic variation) and mark-recapture studies in nature, molecular and quantitative genetic analyses in the laboratory, and fitness assays in semi-natural and laboratory conditions. The results from this research will illustrate to what extent gene flow and maternal effects influence variation in the phenotypes that we see in nature, and how they can affect the ability of organisms to adapt to novel environments. Ultimately this research aims at understanding the short-term ecological and evolutionary processes that create, maintain and change biological diversity, and will be of broad significance for evolutionary biology as well as conservation biology.