Abstracts (first author)
Red grouse (Lagopus lagopus scoticus) in Ireland and Scotland: Adaptive genetic divergence and implications for conservationPDF
Adaptive genetic variation is central to the survival of endangered populations, because it forms the evolutionary potential to respond to future challenges in a changing environment. Divergence in genetic variation among populations, however, has significant implications for conservation purposes. We here present a classical applied conservation biology question and base our answer on evolutionary concepts like selection, drift and adaptation: In Ireland, the Red grouse (Lagopus lagopus scoticus) is believed to be in risk of extinction, whereas it is rather abundant in Scotland and England. It has been proposed to restock the fragmented Irish populations with individuals from Scotland. We address the question whether Red grouse populations in Ireland and Scotland show significant divergence in adaptive genetic variation. If so, they should be recognized as separated evolutionary lineages for conservation purposes. Using 454-pyrosequencing we analysed immune genes of the MHC class II (Major histocompatibility complex), which are popular candidate genes to study adaptive genetic diversity due to their key role in many biological processes like pathogen resistance and mate choice. We compared the results with a study on neutral microsatellite variation to distinguish between genetic drift and selection. We found clear footprints of selection acting on the MHC genes, as well as variation in the number of gene copies, another classical feature of MHC evolution. The differentiation of adaptive genetic variation between Ireland and Scotland was strong with an Fst of 0.11, and significantly higher than differentiation based on neutral microsatellite variation with an Fst of 0.068. Thus, we conclude that these large differences in adaptive genetic variation are not due to drift and we advise against the introduction of Scottish Red grouse to supplement Irish populations. Instead we propose that efforts should be made to increase gene flow between Irish subpopulations.