Multiple glacial refugia and contemporary dispersal shape the genetic structure of an endemic amphibian from the Pyrenees

Historical factors (colonization scenarios, demographic oscillations) and contemporary processes (population connectivity, current population size) largely contribute to shaping species’ present-day genetic diversity and structure. In this study, we use a combination of mitochondrial and nuclear DNA markers to understand the role of Quaternary climatic oscillations and present-day gene flow dynamics in determining the genetic diversity and structure of the newt Calotriton asper (Al. Dugès, 1852), endemic to the Pyrenees. Mitochondrial DNA did not show a clear phylogeographic pattern and presented low levels of variation. In contrast, microsatellites revealed five major genetic lineages with admixture patterns at their boundaries. Approximate Bayesian computation analyses and linear models indicated that the five lineages likely underwent separate evolutionary histories and can be tracked back to distinct glacial refugia. Lineage differentiation started around the Last Glacial Maximum at...

历史因素（拓殖情景、种群数量波动）与当代过程（种群连通性、当前种群规模）在很大程度上塑造了物种现今的遗传多样性与群体遗传结构。本研究结合线粒体DNA（mitochondrial DNA）与核DNA分子标记，旨在探究第四纪气候波动以及当代基因流动态，对比利牛斯山特有物种肋突螈（Calotriton asper, Al. Dugès, 1852）的遗传多样性与群体遗传结构的影响。线粒体DNA未呈现清晰的系统地理格局，且变异水平较低。与之相反，微卫星标记（microsatellite）揭示了五大主要遗传谱系，其交界区域存在基因混合模式。近似贝叶斯计算（Approximate Bayesian Computation）分析与线性模型结果表明，这五大谱系大概率经历了独立的演化历史，且可追溯至不同的冰期避难所。谱系分化始于末次冰盛期前后，具体起始于……