Data from: Congruent signals of population history but radically different patterns of genetic diversity between mitochondrial and nuclear markers in a mountain lizard

Historical factors, current population size, population connectivity and selective processes at linked loci contribute to shaping contemporary patterns of neutral genetic diversity. It is now widely acknowledged that nuclear and mitochondrial markers react differently to current demography as well as to past history, so the use of both types of markers is often advocated to gain insight on both historical and contemporary processes. We used 12 microsatellite loci genotyped in 13 populations of a mountain lizard (Iberolacerta bonnali) to test if the historical scenario favoured by a previous mitochondrial study was also supported by nuclear markers and thereby evaluated the consequences of post-glacial range movements on nuclear diversity. Congruent signals of recent history were revealed by nuclear and mitochondrial markers using an Approximate Bayesian Computation approach but contemporary patterns of mtDNA and nuclear DNA diversity were radically different. Although dispersal in this species is probably highly restricted at all spatial scales, colonisation abilities have been historically good, suggesting capability for reestablishment of locally extinct populations except in fully disconnected habitats.

历史因素、当前种群规模、种群连通性以及连锁位点的选择过程，共同塑造了当代中性遗传多样性的分布模式。目前学界已普遍认可，核标记（nuclear markers）与线粒体标记（mitochondrial markers）对当前种群动态及过往历史的响应模式存在差异，因此学界常倡导同时使用两类标记，以同时解析历史与当代的演化过程。本研究对13个山地蜥蜴（Iberolacerta bonnali）种群的12个微卫星位点（microsatellite loci）进行基因分型，旨在验证此前一项线粒体研究支持的历史演化情景是否也能得到核标记的支持，进而评估冰期后分布区迁移对核遗传多样性的影响。通过近似贝叶斯计算（Approximate Bayesian Computation, ABC）方法分析，核标记与线粒体标记均揭示了与近期历史一致的演化信号，但线粒体DNA（mtDNA）与核DNA的当代多样性分布模式却存在显著差异。尽管该物种的扩散能力在所有空间尺度上可能都极为有限，但其历史上的定殖能力较强，这意味着除了完全连通性丧失的生境外，该物种具备重建局地灭绝种群的潜力。