Data from: Imprints of multiple glacial refugia in the Pyrenees revealed by phylogeography and palaeodistribution modelling of an endemic spider

Mediterranean mountain ranges harbour highly endemic biota in islandlike habitats. Their topographic diversity offered the opportunity for mountain species to persist in refugial areas during episodes of major climatic change. We investigate the role of Quaternary climatic oscillations in shaping the demographic history and distribution ranges in the spider Harpactocrates ravastellus, endemic to the Pyrenees. Gene trees and multispecies coalescent analyses on mitochondrial and nuclear DNA sequences unveiled two distinct lineages with a hybrid zone around the northwestern area of the Catalan Pyrenees. The lineages were further supported by morphological differences. Climatic niche-based species distribution models (SDMs) identified two lowland refugia at the western and eastern extremes of the mountain range, which would suggest secondary contact following postglacial expansion of populations from both refugia. Neutrality test and approximate Bayesian computation (ABC) analyses indicated that several local populations underwent severe bottlenecks followed by population expansions, which in combination with the deep population differentiation provided evidence for population survival during glacial periods in microrefugia across the mountain range, in addition to the main Atlantic and Mediterranean (western and eastern) refugia. This study sheds light on the complexities of Quaternary climatic oscillations in building up genetic diversity and local endemicity in the southern Europe mountain ranges.

地中海山脉在类岛屿生境中孕育着高度特有的生物区系。其复杂的地形多样性为山地物种在重大气候波动时期于避难所中存续提供了可能。本研究以比利牛斯山特有蜘蛛物种*Harpactocrates ravastellus*为研究对象，探究第四纪气候振荡对其种群历史与分布范围的塑造作用。基于线粒体DNA（mitochondrial DNA）与核DNA（nuclear DNA）序列的基因树及多物种溯祖分析显示，存在两个独立演化支，二者在加泰罗尼亚比利牛斯山西北部区域形成了杂交带。二者的形态差异进一步佐证了这两个演化支的划分。基于气候生态位的物种分布模型（Species Distribution Models, SDMs）识别出该山脉东西两端各存在一处低地避难所，这表明两个避难所的种群在冰期后扩张过程中发生了二次接触。中性检验与近似贝叶斯计算（Approximate Bayesian Computation, ABC）分析表明，多个本地种群在经历严重的瓶颈效应后发生了种群扩张；结合深度种群分化结果，这证明除了主要的大西洋与地中海（东西两侧）避难所外，该山脉各处的微型避难所也为种群在冰期的存续提供了支撑。本研究揭示了第四纪气候振荡在塑造南欧山地物种遗传多样性与局地特有性过程中的复杂机制。