Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA.
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
Nat Ecol Evol. 2018 Apr;2(4):688-696. doi: 10.1038/s41559-018-0494-6. Epub 2018 Mar 12.
The Cretaceous-Palaeogene (K-Pg) mass extinction is linked to the rapid emergence of ecologically divergent higher taxa (for example, families and orders) across terrestrial vertebrates, but its impact on the diversification of marine vertebrates is less clear. Spiny-rayed fishes (Acanthomorpha) provide an ideal system for exploring the effects of the K-Pg on fish diversification, yet despite decades of morphological and molecular phylogenetic efforts, resolution of both early diverging lineages and enormously diverse subclades remains problematic. Recent multilocus studies have provided the first resolved phylogenetic backbone for acanthomorphs and suggested novel relationships among major lineages. However, these new relationships and associated timescales have not been interrogated using phylogenomic approaches. Here, we use targeted enrichment of >1,000 ultraconserved elements in conjunction with a divergence time analysis to resolve relationships among 120 major acanthomorph lineages and provide a new timescale for acanthomorph radiation. Our results include a well-supported topology that strongly resolves relationships along the acanthomorph backbone and the recovery of several new relationships within six major percomorph subclades. Divergence time analyses also reveal that crown ages for five of these subclades, and for the bulk of the species diversity in the sixth, coincide with the K-Pg boundary, with divergences between anatomically and ecologically distinctive suprafamilial clades concentrated in the first 10 million years of the Cenozoic.
白垩纪-古近纪（K-Pg）大灭绝与陆地脊椎动物中生态上有明显差异的高等分类群（例如科和目）的快速出现有关，但它对海洋脊椎动物多样性的影响尚不明确。有刺射线鱼类（棘鳍鱼类）为探索 K-Pg 对鱼类多样性的影响提供了一个理想的系统，但尽管经过几十年的形态学和分子系统发育研究，早期分化的谱系和极其多样化的亚科的分辨率仍然存在问题。最近的多基因座研究为棘鳍鱼类提供了第一个已解决的系统发育骨干，并提出了主要谱系之间的新关系。然而，这些新的关系和相关的时间尺度尚未通过系统基因组学方法进行检验。在这里，我们使用超过 1000 个超保守元件的靶向富集，结合分化时间分析，解决了 120 个主要棘鳍鱼类谱系之间的关系，并为棘鳍鱼类辐射提供了一个新的时间尺度。我们的结果包括一个支持度很强的拓扑结构，该结构强烈解决了棘鳍鱼类骨干的关系，并恢复了六个主要鲈形亚目中的几个新关系。分化时间分析还表明，这五个亚科中的五个亚科的冠层年龄，以及第六个亚科的大部分物种多样性的冠层年龄，都与 K-Pg 边界同时发生，在新生代的前 1000 万年中，形态学和生态上有明显差异的超家族分支之间的分歧集中发生。
