Sea ice loss increases genetic isolation in a high Arctic ungulate metapopulation

作者：Bart Peeters, Mathilde Le Moullec, Joost A. M. Raeymaekers, Jonatan Marquez, Knut H. Røed, Åshild Ønvik Pedersen, Vebjørn Veiberg, Leif Egil Loe, Brage Bremset Hansen · 发表于：Global Change Biology · 年份：2019 · DOI：10.1111/gcb.14965 · 被引用次数：32 · 研究领域：Indigenous Studies and Ecology、Genetic and phenotypic traits in livestock、Genetic diversity and population structure

Abstract Sea ice loss may have dramatic consequences for population connectivity, extinction–colonization dynamics, and even the persistence of Arctic species subject to climate change. This is of particular concern in face of additional anthropogenic stressors, such as overexploitation. In this study, we assess the population‐genetic implications of diminishing sea ice cover in the endemic, high Arctic Svalbard reindeer ( Rangifer tarandus platyrhynchus ) by analyzing the interactive effects of landscape barriers and reintroductions (following harvest‐induced extirpations) on their metapopulation genetic structure. We genotyped 411 wild reindeer from 25 sampling sites throughout the entire subspecies' range at 19 microsatellite loci. Bayesian clustering analysis showed a genetic structure composed of eight populations, of which two were admixed. Overall population genetic differentiation was high (mean F ST = 0.21). Genetic diversity was low (allelic richness [AR] = 2.07–2.58; observed heterozygosity = 0.23–0.43) and declined toward the outer distribution range, where populations showed significant levels of inbreeding. Coalescent estimates of effective population sizes and migration rates revealed strong evolutionary source–sink dynamics with the central population as the main source. The population genetic structure was best explained by a landscape genetics model combining strong isolation by glaciers and open water, and high connectivity by dispersal across winter sea ic...