Phylogeography, hybridization, and species discovery in the Etheostoma nigrum complex (Percidae: Etheostoma: Boleosoma)
Phylogeography, hybridization, and species discovery in the Etheostoma nigrum complex (Percidae: Etheostoma: Boleosoma)
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Etheostoma nigrum 复合体的系统发育地理学、杂交和物种发现（鲈科：Etheostoma：Boleosoma）
DOI：
10.1016/j.ympev.2022.107645
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发表时间：
2023
影响因子：
4.1
通讯作者：
Near, Thomas J.
中科院分区：
文献类型：
--
作者：
MacGuigan, Daniel J.;Orr, Oliver D.;Near, Thomas J.
河流鱼类多样化的历史在很大程度上是地理隔离的产物。减少或消除种群之间基因流动的物理障碍通过遗传漂变和自然选择促进了分化，最终导致物种形成。对淡水生物来说，多样化往往是流域重新安排的产物。在孤立的历史是最近的年轻分支中，进化关系可以像一个纠结的网络。其中一个特别的淡水鱼类种群是Johnny Darter（Etheostoma nigrum）物种复合体，传统的分类学和分子生物学表明了基因流动的历史和物种多样性的相互矛盾的推论。在这里，我们组装一个基因组数据集，使用双消化限制性位点相关DNA（ddRAD）测序，并使用双酶切基因组和人口遗传学方法来调查复杂的物种，包括进化历史。nigrum、黑穗草E. olmstedi、艾美球虫E. perlongum和E. suspicious.我们揭示和验证了几个进化谱系，我们划定为物种，强调需要额外的工作，正式描述的多样性theTheostoma nigrum复杂。我们的分析还确定了最近分化的谱系之间的基因流，包括一个涉及E的实例。苏氏原住民，一种本地化的濒危物种。theEtheostoma nigrum物种复杂的系统地理结构与重大地质事件相吻合，如在上新世大西洋沿岸平原的洪水和多个向北的冰川后殖民路线跟踪流域重排流域的平行分歧。我们的研究是一个微妙的例子，说明了北美东部断开的河流系统之间的低扩散率加上地理隔离是如何产生世界淡水生物多样性热点之一的。
The history of riverine fish diversification is largely a product of geographic isolation. Physical barriers that reduce or eliminate gene flow between populations facilitate divergence via genetic drift and natural selection, eventually leading to speciation. For freshwater organisms, diversification is often the product of drainage basin rearrangements. In young clades where the history of isolation is the most recent, evolutionary relationships can resemble a tangled web. One especially recalcitrant group of freshwater fishes is the Johnny Darter (Etheostoma nigrum) species complex, where traditional taxonomy and molecular phylogenetics indicate a history of gene flow and conflicting inferences of species diversity. Here we assemble a genomic dataset using double digest restriction site associated DNA (ddRAD) sequencing and use phylogenomic and population genetic approaches to investigate the evolutionary history of the complex of species that includesE. nigrum, E. olmstedi, E. perlongum,andE. susanae. We reveal and validate several evolutionary lineages that we delimit as species, highlighting the need for additional work to formally describe the diversity of theEtheostoma nigrumcomplex. Our analyses also identify gene flow among recently diverged lineages, including one instance involvingE. susanae, a localized and endangered species. Phylogeographic structure within theEtheostoma nigrumspecies complex coincides with major geologic events, such as parallel divergence in river basins during Pliocene inundation of the Atlantic coastal plain and multiple northward post-glacial colonization routes tracking river basin rearrangements. Our study serves as a nuanced example of how low dispersal rates coupled with geographic isolation among disconnected river systems in eastern North America has produced one of the world’s freshwater biodiversity hotspots.