Museo Nacional de Ciencias Naturales (MNCN-CSIC), C/José Gutiérrez Abascal, 2, 28006 Madrid, Spain.
Mol Phylogenet Evol. 2011 Jul;60(1):170-82. doi: 10.1016/j.ympev.2011.04.006. Epub 2011 Apr 22.
The Pleistocene was characterized by climatic changes that greatly altered the distribution of organisms. Population extinctions, bottlenecks, isolation, range expansions and contractions were often associated with glaciations, leaving signatures in the spatial patterns of genetic diversity across species. Lissotriton helveticus belongs to a Pan-European lineage of newts that were strongly affected by glaciations and represent an excellent model to analyse the effect of generalized climatic changes in phylogeographic patterns. We studied the genetic diversity of the species using data from two mitochondrial and three nuclear genes analyzed in a Bayesian phylogenetic framework to investigate the historical processes shaping spatial patterns of genetic diversity. Mitochondrial haplotypes cluster in four different groups present in the Iberian Peninsula and of Pleistocene origin, probably by allopatric fragmentation. Nuclear genes present no obvious geographic structure patterns, suggesting gene flow and generalized incomplete lineage sorting. Populations north of the Pyrenees are closely related to those from northeastern Iberia, suggesting recent range expansion from this region. Historical demographic analyses indicate a demographic expansion starting about 100,000years ago and more recent population declines. Compared to other Lissotriton species, L. helveticus includes only relatively young genetic lineages, suggesting a Central European pre-Pleistocene distribution followed by complete extirpation of the species during glaciations in that area. Historical demographic trends in the Iberian Peninsula are reversed with respect to the more Mediterranean species Lissotriton boscai, indicating different responses of both species to climate changes. Diversity patterns among Lissotriton species seem to be defined by four main factors: ancestral distributions, colonization capabilities, interactions with other species and effective population sizes. Differences in these factors define two types of species, referred to as "R" (refugia) and "S" (sanctuaries) that explain part of the diversity in patterns of genetic diversity created by glaciations in Western Europe.
更新世的特点是气候的变化，这些变化极大地改变了生物的分布。物种灭绝、瓶颈效应、隔离、范围扩大和收缩通常与冰川作用有关，在物种的遗传多样性的空间模式中留下了痕迹。Lissotriton helveticus 属于欧洲蝾螈的一个谱系，它们受到冰川作用的强烈影响，是分析广义气候变化对系统地理格局影响的理想模式。我们使用来自两个线粒体和三个核基因的数据研究了该物种的遗传多样性，这些数据在贝叶斯系统发育框架中进行了分析，以研究塑造遗传多样性空间模式的历史过程。线粒体单倍型聚类为四个不同的组，存在于伊比利亚半岛，起源于更新世，可能是由于地理隔离而产生的。核基因没有明显的地理结构模式，表明基因流和广义不完全谱系分选。比利牛斯山脉以北的种群与伊比利亚东北部的种群密切相关，表明最近从该地区扩张了范围。历史人口动态分析表明，种群扩张始于约 10 万年前，最近人口减少。与其他 Lissotriton 物种相比，L. helveticus 只包含相对年轻的遗传谱系，这表明该物种在更新世前在中欧的分布，随后在该地区的冰川作用下完全灭绝。伊比利亚半岛的历史人口动态趋势与更具地中海特征的 Lissotriton boscai 相反，表明这两个物种对气候变化的反应不同。Lissotriton 物种之间的多样性模式似乎由四个主要因素决定：祖先分布、殖民能力、与其他物种的相互作用和有效种群大小。这些因素的差异定义了两种类型的物种，称为“R”（避难所）和“S”（庇护所），它们解释了由西欧冰川作用造成的遗传多样性模式多样性的一部分。
