Data from: Genetic diversity and historical biogeography of the Maltese wall lizard, Podarcis filfolensis (Squamata: Lacertidae)

Podarcis filfolensis is an endemic lizard from the Maltese archipelago. There is evidence of human-mediated decline and even extirpation of some insular populations of this species. However, information about the intraspecific genetic diversity and phylogeographic patterns of this species is limited. Here we analyze genetic markers from a multi-locus dataset (mtDNA, 2,533 bp; nuclear c-mos gene, 353 bp; 11 microsatellites) for individuals from extant populations of P. filfolensis. Despite generally low genetic variability, two main mitochondrial groupings were clearly identified. In general, individuals from the main island of Malta were genetically distinct from those from Gozo, Comino, Cominotto and Small Blue Lagoon Rock, and also from Linosa and Lampione individuals. Three genetic clusters were detected based on microsatellite data: one was found at higher frequency on Malta, while the other two included samples from the remaining islands, showing some concordance with the mtDNA pattern. A time-calibrated Bayesian tree for the principal mitochondrial lineages indicated strong statistical support for two P. filfolensis lineages that originated in the Pleistocene (105.4–869 Ka). We show that these lineages largely meet the criteria for recognition as evolutionary significant units despite some recent admixture (possibly due to recent translocations between islands). Human disturbance, low genetic variability, evidence of bottlenecks and extirpation on one island indicate that a thorough review of the current conservation status of P. filfolensis would be timely.

Podarcis filfolensis是马耳他群岛特有的蜥蜴。已有研究证据表明，人类活动介导了该物种部分岛屿种群的衰退，甚至局部灭绝。然而，目前关于该种种内遗传多样性与系统地理格局的相关信息仍较为匮乏。本研究针对现存的P. filfolensis种群个体，采用多位点数据集（线粒体DNA（mtDNA），2533 bp；核c-mos基因，353 bp；11个微卫星位点）开展遗传标记分析。尽管整体遗传变异水平偏低，研究仍明确鉴定出两个主要的线粒体支系。总体而言，马耳他主岛的个体与戈佐岛、科米诺岛、科米诺托岛以及小蓝礁湖岩的个体，以及林杜萨岛和兰皮奥内岛的个体均存在显著遗传分化。基于微卫星数据，本研究共检测到三个遗传聚类：其中一个聚类在马耳他岛的个体中出现频率更高，另外两个聚类则涵盖其余岛屿的采样个体，该结果与线粒体DNA的支系模式存在一定程度的一致性。针对主要线粒体支系构建的时间校准贝叶斯系统发育树显示，两个P. filfolensis支系起源于更新世（105.4~869 Ka），该演化关系具有较强的统计支持度。研究表明，尽管存在近期的基因混合（可能源于岛屿间的近期物种易位），但这两个支系基本满足进化显著单元（evolutionary significant unit）的认定标准。人类活动干扰、较低的遗传变异水平、种群瓶颈效应证据以及某一岛屿种群的局部灭绝，均提示亟需对P. filfolensis的当前保护现状开展全面评估。