Inter and intra‐population phenotypic and genotypic structuring in the European whitefish Coregonus lavaretus,a rare freshwater fish in Scotland |
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| Authors: | C. E. Adams C. W. Bean J. A. Dodd A. Down E. C. Etheridge A. R. D. Gowans O. Hooker R. Knudsen A. A. Lyle I. J. Winfield K. Præbel |
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| Affiliation: | 1. Scottish Centre for Ecology and the Natural Environment, University of Glasgow, Glasgow G63 0AW, U.K.;2. Scottish Natural Heritage, Caspian House, Glasgow G81 2NR, U.K.;3. Environment Agency, Penrith, Cumbria CA11 9BP, U.K.;4. Department of Arctic and Marine Biology, UiT The Arctic University of Norway, N‐9037 Troms?, Norway;5. Lake Ecosystems Group, Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster LA1 4AP, U.K. |
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| Abstract: | This study revealed between‐lake genetic structuring between Coregonus lavaretus collected from the only two native populations of this species in Scotland, U.K. (Lochs Eck and Lomond) evidenced by the existence of private alleles (12 in Lomond and four in Eck) and significant genetic differentiation (FST = 0·056) across 10 microsatellite markers. Juvenile C. lavaretus originating from eggs collected from the two lakes and reared in a common‐garden experiment showed clear phenotypic differences in trophic morphology (i.e. head and body shape) between these populations indicating that these characteristics were, at least partly, inherited. Microsatellite analysis of adults collected from different geographic regions within Loch Lomond revealed detectable and statistically significant but relatively weak genetic structuring (FST = 0·001–0·024) and evidence of private alleles related to the basin structure of the lake. Within‐lake genetic divergence patterns suggest three possibilities for this observed pattern: (1) differential selection pressures causing divergence into separate gene pools, (2) a collapse of two formerly divergent gene pools and (3) a stable state maintained by balancing selection forces resulting from spatial variation in selection and lake heterogeneity. Small estimates of effective population sizes for the populations in both lakes suggest that the capacity of both populations to adapt to future environmental change may be limited. |
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| Keywords: | early divergence ecological evolution environmental change genetic structure microsatellite markers speciation |
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