A new phylogeographic perspective on a classical refugial area - colonization patterns and geneflow of spectacled salamanders (genus Salamandrina) in Italy

意大利半岛被认为是欧洲冰河时期的主要避难所之一。对意大利各种分类群的系统地理学研究发现，最南端（卡拉布里亚）与北部地区相比，拥有更强烈的分化谱系。我们计划阐明意大利特有的两种不同的眼镜蝾螈（Salamandrina perspicillata）和S. terdigitata的进化历史。这些谱系在几百万年前就分裂了，而S. perspicillata只在北方发现，S. terdigitata则局限于南方。人们原以为南方物种的遗传多样性要高得多，但对这些物种的系统地理学的初步数据表明，它们的遗传多样性模式与在合位两栖动物物种中发现的遗传多样性模式完全不一致。这两个物种的遗传分化似乎都非常低。因此，尽管它们各自独立的进化历史，但在这两个物种的区域内，相似或可能相同的机制一定独立地塑造了种群结构。此外，我们还将分析Lepini山区细尺度的perspicillata群体遗传结构，以帮助了解在已知生态和生活史参数的（亚）群体间传播的空间尺度上的遗传多样性水平和基因流动。这项研究在样本量和分析的标记数量方面将是前所未有的，我们希望在不同的地理尺度上找到一个很好的近似真实的人口历史。

Peninsular Italy is considered one of the main ice-age refugia of Europe. Phylogeographic studies of various Italian taxa have found that the southernmost part (Calabria) harbors more strongly differentiated lineages compared to northern regions. We plan to elucidate the evolutionary history of the two distinct species of spectacled salamanders, Salamandrina perspicillata and S. terdigitata, which are endemic to Italy. These lineages split several million years ago and while S. perspicillata is only found in north, S. terdigitata is restricted to the south. One would expect much higher genetic diversity in the southern species, but preliminary data on the phylogeography of these species indicate a pattern of genetic diversity that is in complete discordance with those found in syntopic amphibian species. Genetic differentiation seems remarkably low in both species. Thus, despite their independent evolutionary history, similar or maybe the same mechanisms must have shaped the population structure within the area of both species independently. Additionally, we will analyze the finescale population genetic structure of S. perspicillata in the Lepini Mountains to help understand the level genetic diversity within and gene flow on the spatial scale of dispersal among (sub)populations, for which ecological and life-history parameter are well known. This study will be unprecedented in regard to sample size and numbers of markers analyzed, and we expect to find a good approximation of the true demographic histories on different geographic scales.