Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary
Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary
复制标题
系统基因组学揭示了白垩纪-古近纪边界冈瓦纳蛙三个主要分支的快速、同时多样化
DOI：
10.1073/pnas.1704632114
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发表时间：
2017-07-18
影响因子：
11.1
通讯作者：
Zhang, Peng
中科院分区：
文献类型：
--
作者：
Feng, Yan-Jie;Blackburn, David C.;Zhang, Peng
青蛙（无尾动物）是最多样化的脊椎动物之一，占现存两栖动物物种的近90%。它们在世界范围内的分布和多样性使它们非常适合评估进化、生态和保护方面的基本问题。然而，尽管它们具有重要的科学意义，但青蛙多样化的进化史和速度仍然知之甚少。通过使用前所未有的分子数据集，包括156种青蛙的95个核基因的88kb字符，结合20个基于化石的校准，我们的分析结果最有力地支持了所有主要青蛙谱系的系统发育，并提供了青蛙进化的时间尺度，表明分化时间比早期研究提出的要早得多。出乎意料的是，我们的分化时间分析表明，在白垩纪-古近纪（K-Pg）边界（KPB），三个物种丰富的分支（Hyloidea， Microhylidae和Natatanura）同时经历了快速多样化，占现存无脊椎动物物种的88%。此外，包含树栖物种的无脊椎动物科和亚科起源于KPB附近或之后。这些结果表明，K-Pg大灭绝可能通过创造新的生态机会引发了蛙类的爆炸性辐射。这种系统发育也揭示了一些关系，如小蛙科是所有其他蛙类的姐妹，Natatanura的非洲大陆谱系形成了一个分支，是欧亚、印度、美拉尼西亚和马达加斯加谱系的姐妹。生物地理学分析表明，现代青蛙的祖先地区是非洲，它们目前的分布在很大程度上与泛大陆的分裂和随后的冈瓦南分裂有关。
Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise similar to 88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous-Paleogene (K-Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K-Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation.