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.

地中海山脉的类岛屿生境中孕育着高度特有的生物类群。其复杂的地形多样性为山地物种在大规模气候变化事件中于避难所区域存续提供了有利条件。本研究以比利牛斯山脉特有蜘蛛物种*Harpactocrates ravastellus*为研究对象，探讨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与核DNA序列的基因树及多物种溯祖分析表明，该物种存在两个显著分化的支系，二者在加泰罗尼亚比利牛斯山脉西北部区域形成杂交带。这两支系的分化还得到了形态学差异的佐证。基于气候生态位的物种分布模型（SDMs）识别出该山脉东西两端各存在一处低地避难所，该结果暗示两个避难所的种群在冰期后扩张后发生了二次接触。中性检验与近似贝叶斯计算（ABC）分析结果显示，多个当地种群经历了严重的种群瓶颈事件后发生了种群扩张；结合深度种群分化现象，这证明除大西洋与地中海（东西两侧）的主要避难所外，该山脉各处的微避难所同样为种群在冰期的存续提供了条件。本研究阐明了第四纪气候振荡在塑造南欧山脉遗传多样性与区域特有性过程中的复杂机制。