Muñoz-Mendoza Carla, D'Elía Guillermo, Panzera Alejandra, Méndez T Marco A, Villalobos-Leiva Amado, Sites Jack W, Victoriano Pedro F
Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, Chile.
Mol Phylogenet Evol. 2017 Nov;116:157-171. doi: 10.1016/j.ympev.2017.08.016. Epub 2017 Sep 5.
The complex orogenic history and structure of Southern South America, coupled with Pleistocene glacial cycles, have generated paleoclimatic and environmental changes that influenced the spatial distribution and genetic composition of natural populations. Despite the increased number of phylogeographic studies in this region and given the frequent idiosyncratic phylogeographic patterns, there is still the need to focus research especially on species that are currently distributed within a wide range of bioclimatic regimes, and that historically have been subject to contrasting scenarios. Liolaemus tenuis is a widely distributed lizard species inhabiting latitudinally in almost 1000km through central and southern Chile. Here we describe the geographical patterns of genetic variation and lineage diversification within L. tenuis, and their association with geography and Pleistocene glaciations, using sequences from one mitochondrial and two nuclear genes, and five microsatellite loci, and covering most of the species distributional range. Our results revealed a high diversity both within and among populations, as well as two phylogeographic breaks, which are consistent with two of the larger rivers of central Chile, the Maipo and Biobío Rivers. Liolaemus tenuis is characterized by several allopatric lineages, especially in its north and central range, which suggest a history of multiple vicariance processes. Conversely, populations found in the southern range, south of the Biobío River, show signatures of recent decreases in effective population sizes, coupled with recent range expansions and secondary contact. Niche "envelope" data are consistent with patterns of genetic variation; both suggest a history of discontinuous areas of relatively stable populations throughout all of the distribution of L. tenuis. These data are also consistent with higher probabilities of habitat suitability north of the Maipo River (ca. 33°S), in both coastal areas and the "Intermediate Depression" between 34° and 37°S, as well as in the southern Coastal Cordillera between the Biobío and Araucanía regions. Interestingly, both molecular and niche envelope modeling data suggest that some populations may have persisted in fragmented refugia in Andean valleys, within the limits of the ice sheet. Finally, our results suggest that several populations of L. tenuis colonized glaciated regions from refugial areas in lowlands and coastal regions, and in the southern distribution, historic migration events would have occurred from refugial areas within the limits of the ice sheet.
南美洲南部复杂的造山历史和结构，再加上更新世冰川周期，引发了古气候和环境变化，这些变化影响了自然种群的空间分布和遗传组成。尽管该地区系统发育地理学研究的数量有所增加，且考虑到频繁出现的独特系统发育地理模式，但仍有必要将研究重点尤其放在目前分布于广泛生物气候区域内、且历史上经历过不同情况的物种上。细薄岩鬣蜥是一种分布广泛的蜥蜴物种，在智利中部和南部沿纬度方向分布近1000公里。在此，我们利用来自一个线粒体基因、两个核基因的序列以及五个微卫星位点，并覆盖该物种大部分分布范围，描述了细薄岩鬣蜥内部遗传变异和谱系多样化的地理模式，以及它们与地理和更新世冰川作用的关联。我们的结果揭示了种群内部和种群之间的高度多样性，以及两个系统发育地理间断，这与智利中部的两条较大河流——迈波河和比奥比奥河一致。细薄岩鬣蜥的特征是有几个异域谱系，特别是在其北部和中部分布范围内，这表明存在多次隔离分化过程的历史。相反，在比奥比奥河以南的南部分布范围内发现的种群，显示出有效种群大小近期下降的特征，同时伴有近期的范围扩张和二次接触。生态位“包络”数据与遗传变异模式一致；两者都表明在细薄岩鬣蜥的整个分布范围内，存在相对稳定种群的不连续区域的历史。这些数据也与迈波河以北（约南纬33°）、沿海地区以及南纬34°至37°之间的“中间凹陷地带”，以及比奥比奥河和阿劳卡尼亚地区之间的南部沿海山脉中更高的栖息地适宜性概率一致。有趣的是，分子数据和生态位包络模型数据都表明，一些种群可能在安第斯山谷的碎片化避难所中得以存续，处于冰盖范围之内。最后，我们的结果表明，细薄岩鬣蜥的几个种群从低地和沿海地区的避难所区域殖民到了冰川覆盖地区，并且在南部分布中，历史上的迁徙事件可能发生在冰盖范围之内的避难所区域。
