Zoological Institute, Technische Universität Braunschweig, Mendelssohnstrasse 4, 38106 Braunschweig, Germany.
Zoological Institute, Technische Universität Braunschweig, Mendelssohnstrasse 4, 38106 Braunschweig, Germany; Department of Natural Resources, Isfahan University of Technology, Isfahan, Iran.
Mol Phylogenet Evol. 2019 Apr;133:189-197. doi: 10.1016/j.ympev.2019.01.003. Epub 2019 Jan 16.
We reconstruct the molecular phylogeny of Near Eastern mountain brook newts of the genus Neurergus (family Salamandridae) based on newly determined RADseq data, and compare the outcomes of concatenation-based phylogenetic reconstruction with species-tree inference. Furthermore, we test the current taxonomy of Neurergus (with four species: Neurergus strauchii, N. crocatus, N. kaiseri, and N. derjugini) against coalescent-based species-delimitation approaches of our genome-wide genetic data set. While the position of N. strauchii as sister species to all other Neurergus species was consistent in all of our analyses, the phylogenetic relationships between the three remaining species changed depending on the applied method. The concatenation approach, as well as quartet-based species-tree inference, supported a topology with N. kaiseri as the closest relative to N. derjugini, while full-coalescent species-tree inference approaches supported N. crocatus as sister species of N. derjugini. Investigating the individual signal of gene trees highlighted an extensive variation among gene histories, most likely resulting from incomplete lineage sorting. Coalescent-based species-delimitation models suggest that the current taxonomy might underestimate the species richness within Neurergus and supports seven species. Based on the current sampling, our analysis suggests that N. strauchii, N. derjugini and N. kaiseri might each be subdivided into further species. However, as amphibian species are known to be composed of deep conspecific lineages that do not always warrant species status, these results need to be cautiously interpreted in an integrative taxonomic framework. We hypothesize that the rather shallow divergences detected within N. kaiseri and N. derjugini likely reflect an ongoing speciation process and thus require further investigation. On the contrary, the much deeper genetic divergence found between the two morphologically and geographically differentiated subspecies of N. strauchii leads us to propose that N. s. barani should be considered a distinct species, Neurergus barani Öz, 1994.
我们基于新测定的 RADseq 数据重建了近东山溪蝾螈属（有尾目蝾螈科）的分子系统发育，并比较了基于串联的系统发育重建与物种树推断的结果。此外，我们还利用我们的全基因组遗传数据集的基于合并的物种界定方法来检验 Neurergus（有四个物种： Neurergus strauchii、N. crocatus、N. kaiseri 和 N. derjugini）的当前分类。虽然在我们所有的分析中，N. strauchii 作为所有其他 Neurergus 物种的姐妹种的位置都是一致的，但在剩余的三个物种之间的系统发育关系因所应用的方法而异。串联方法以及基于四分体的种系发生推断支持了一个拓扑结构，其中 N. kaiseri 是 N. derjugini 的最亲近的亲戚，而全合并种系发生推断方法则支持 N. crocatus 是 N. derjugini 的姐妹种。研究基因树的个体信号突出了基因历史的广泛变化，这很可能是由于不完全谱系分选造成的。基于合并的物种界定模型表明，当前的分类法可能低估了 Neurergus 内的物种丰富度，并支持七个物种。根据目前的采样情况，我们的分析表明，N. strauchii、N. derjugini 和 N. kaiseri 可能各自分为进一步的物种。然而，由于已知的两栖动物物种由深度的同种谱系组成，这些谱系并不总是具有物种地位，因此需要在综合分类学框架中谨慎解释这些结果。我们假设在 N. kaiseri 和 N. derjugini 中检测到的相对较浅的分歧可能反映了正在进行的物种形成过程，因此需要进一步研究。相反，在 N. strauchii 的两个形态和地理分化亚种之间发现的更深的遗传差异使我们提出 N. s. barani 应该被视为一个独特的物种， Neurergus barani Öz，1994。
