Recent Diversification of a Marine Genus (Tursiops spp.) Tracks Habitat Preference and Environmental Change
Recent Diversification of a Marine Genus (Tursiops spp.) Tracks Habitat Preference and Environmental Change
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DOI：
10.1093/sysbio/syt051
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发表时间：
2013-11-01
影响因子：
6.5
通讯作者：
Hoelzel, A. Rus
中科院分区：
文献类型：
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作者：
Moura, Andre E.;Nielsen, Sandra C. A.;Hoelzel, A. Rus
由于海洋生境缺乏明确的界限，特别是海洋哺乳动物等高度移动的物种，使了解海洋系统中多样性的演变和由此产生的系统分类变得混乱。海豚种群和兄弟物种往往表现出沿海和近海生境之间的分化，类似于某些鱼类物种的中上层/沿岸的或底栖分化。在这里，我们测试的假设，血统内的多型属Tursiops跟踪过去的环境变化，反映生态驱动进化促进栖息地释放。我们使用了一个已知的最近的时间点进行校准（博斯普鲁斯海峡的开放）和整个线粒体基因组（有丝分裂基因组）序列的高系统发育分辨率。谱系形成的模式表明起源于澳大拉西亚和几个早期的分支，涉及目前居住在沿海栖息地的形式。中上层环境中的辐射是相对较新的现象，随后很可能会返回某些区域的沿海生境。一些节点定义不同的生态类型内的属聚类的时间最近的两个间冰期的过渡。在末次盛冰期之后的日期也看到了多样化增加的信号。这些数据表明，在地理扩张的栖息地偏好的跟踪，其次是过渡点反映栖息地的变化，这可能与环境变化的时期。[气候振荡;海洋哺乳动物;更新世;辐射;物种形成。]
Understanding the evolution of diversity and the resulting systematics in marine systems is confounded by the lack of clear boundaries in oceanic habitats, especially for highly mobile species like marine mammals. Dolphin populations and sibling species often show differentiation between coastal and offshore habitats, similar to the pelagic/littoral or benthic differentiation seen for some species of fish. Here we test the hypothesis that lineages within the polytypic genus Tursiops track past changes in the environment reflecting ecological drivers of evolution facilitated by habitat release. We used a known recent time point for calibration (the opening of the Bosphorus) and whole mitochondrial genome (mitogenome) sequences for high phylogenetic resolution. The pattern of lineage formation suggested an origin in Australasia and several early divisions involving forms currently inhabiting coastal habitats. Radiation in pelagic environments was relatively recent, and was likely followed by a return to coastal habitat in some regions. The timing of some nodes defining different ecotypes within the genus clustered near the two most recent interglacial transitions. A signal for an increase in diversification was also seen for dates after the last glacial maximum. Together these data suggest the tracking of habitat preference during geographic expansions, followed by transition points reflecting habitat shifts, which were likely associated with periods of environmental change. [Climatic oscillations; marine mammal; pleistocene; radiation; speciation.].