Genomic, ecological, and morphological approaches to investigating species limits: A case study in modern taxonomy from Tropical Eastern Pacific surgeonfishes
Genomic, ecological, and morphological approaches to investigating species limits: A case study in modern taxonomy from Tropical Eastern Pacific surgeonfishes
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DOI：
10.1002/ece3.5029
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发表时间：
2019-03
影响因子：
2.6
通讯作者：
W. B. Ludt;Moisés A. Bernal;Erica Kenworthy;E. Salas;P. Chakrabarty
中科院分区：
文献类型：
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作者：
W. B. Ludt;Moisés A. Bernal;Erica Kenworthy;E. Salas;P. Chakrabarty
摘要各种各样的物种通过轻微的颜色变化来区分。然而，分子分析一再表明，颜色并不总是对应于密切相关的群体之间的不同进化历史，这表明这种特征是不稳定的，可能会误导物种鉴定。在本研究中，我们分析了在热带东太平洋（TEP），这是区分的存在或不存在的黑点在他们的身体上的姐妹种Prionurus surgeonfishes的进化历史。我们使用基于比较标本的方法，线粒体基因（COI），800多个核基因座（超保守元素）和非生物生态位比较来检查该系统中的物种限制。结果表明，有一个完全重叠的分生计数和形态测量之间的两个物种。此外，我们检测到多个个体具有中间斑点图案，表明着色不是诊断性的。线粒体数据恢复了物种和所有位置之间共享的单个主要单倍型，导致完全缺乏结构（ΦST = 0）。基因组分析还表明遗传分化水平较低（F ST = 0.013），并且在两种表型之间没有检测到替代固定的SNP。此外，生态位比较不能排除物种之间的生态位等价性或相似性。这些结果表明，这两种表型是同种和广泛分布的TEP。在这里，我们承认Prionurus punctatus Gill 1862是P. laticlavius（Valenciennes 1846）的初级主观同义词。该物种表型变异的根本原因尚不清楚。然而，这个系统提供了深入了解一般的进化动力学内的TEP。
Abstract A wide variety of species are distinguished by slight color variations. However, molecular analyses have repeatedly demonstrated that coloration does not always correspond to distinct evolutionary histories between closely related groups, suggesting that this trait is labile and can be misleading for species identification. In the present study, we analyze the evolutionary history of sister species of Prionurus surgeonfishes in the Tropical Eastern Pacific (TEP), which are distinguished by the presence or absence of dark spots on their body. We examined the species limits in this system using comparative specimen‐based approaches, a mitochondrial gene (COI), more than 800 nuclear loci (Ultraconserved Elements), and abiotic niche comparisons. The results indicate there is a complete overlap of meristic counts and morphometric measurements between the two species. Further, we detected multiple individuals with intermediate spotting patterns suggesting that coloration is not diagnostic. Mitochondrial data recovered a single main haplotype shared between the species and all locations resulting in a complete lack of structure (ΦST = 0). Genomic analyses also suggest low levels of genetic differentiation (F ST = 0.013), and no alternatively fixed SNPs were detected between the two phenotypes. Furthermore, niche comparisons could not reject niche equivalency or similarity between the species. These results suggest that these two phenotypes are conspecific and widely distributed in the TEP. Here, we recognize Prionurus punctatus Gill 1862 as a junior subjective synonym of P. laticlavius (Valenciennes 1846). The underlying causes of phenotypic variation in this species are unknown. However, this system gives insight into general evolutionary dynamics within the TEP.