The rich genetic and phenotypic diversity of species complexes is best recognized through formal taxonomic naming, but one must first assess the evolutionary history of phylogeographic lineages to identify and delimit candidate taxa. Using genomic markers, mitochondrial DNA barcoding, and morphometric analyses, we examined lineage diversity and distribution in the Iberian endemic frog Rana parvipalmata. We confirmed two deep phylogeographic lineages, one relatively homogenous genetically, found in Asturias and adjacent areas (T2), and one more fragmented and locally genetically impoverished, restricted to Galicia (T1). Analyses of their hybrid zone suggested a shallow transition characterized by far-ranging admixture, which was modelled by a wide geographic cline (~60 km for the genome average) and no obvious barrier loci (i.e. loci showing disproportionally restricted introgression). The relatively young T1 and T2 have thus remained reproductively compatible, which argues against their distinction as biological species, and we accordingly describe T2 as a new subspecies, Rana parvipalmata asturiensis ssp. nov. Remarkably, we highlight striking discordances between mitochondrial and nuclear distributions across their hybrid zones, as well as between their genetic and morphological differentiation. Our study illustrates how genomic-based phylogeographic frameworks can help decipher the high genetic and phenotypic variation of species complexes and substantiate the taxonomic assessment of candidate lineages.

中文翻译：

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界定基因组时代的系统发育地理学多样性：应用于伊比利亚特有青蛙

物种复合体丰富的遗传和表型多样性最好通过正式的分类学命名来识别，但必须首先评估系统发育谱系的进化历史，以识别和界定候选类群。利用基因组标记、线粒体 DNA 条形码和形态分析，我们研究了伊比利亚特有蛙 Rana parvipalmata 的谱系多样性和分布。我们确认了两个深层的系统发育谱系，一个在遗传上相对同质，发现于阿斯图里亚斯和邻近地区（T2），另一个更加破碎且局部遗传贫乏，仅限于加利西亚（T1）。对它们的杂交区的分析表明，存在一个以远距离混合为特征的浅过渡，这是通过广泛的地理谱线（基因组平均约60公里）和没有明显的障碍位点（即显示出不成比例的受限基因渗入的位点）来模拟的。因此，相对年轻的 T1 和 T2 保持了生殖相容性，这与它们作为生物物种的区别相悖，因此我们将 T2 描述为一个新的亚种，即 Rana parvipalmata asturiensis ssp。十一月 值得注意的是，我们强调了线粒体和核分布在其混合区之间以及它们的遗传和形态分化之间的惊人不一致。我们的研究说明了基于基因组的系统发育框架如何帮助破译物种复合体的高度遗传和表型变异，并证实候选谱系的分类学评估。