Neoendemism in Madagascan scaly tree ferns results from recent, coincident diversification bursts
Neoendemism in Madagascan scaly tree ferns results from recent, coincident diversification bursts
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DOI：
10.1111/j.1558-5646.2008.00408.x
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发表时间：
2008-08-01
期刊：
影响因子：
3.3
通讯作者：
Schneider, Harald
中科院分区：
文献类型：
--
作者：
Janssen, Thomas;Bystriakova, Nadia;Schneider, Harald
马达加斯加的12，000种植物中有80%以上是特有的，特有程度高达95%的鳞叶蕨类植物，是马达加斯加万年青雨林中物种丰富的重要组成部分。主要是非洲或亚洲的祖先和分歧的时间通常追溯到马达加斯加从冈瓦纳大陆的分离已经证明了几个马达加斯加动物和被子植物群体。然而，雨林特有谱系的进化研究很少，辐射事件的生态背景也很少被调查。在这里，我们研究的进化，马达加斯加树蕨类植物作为一个雨林特定的模型家庭，整合结果从生物气候生态位分析与过时的系统发育框架，并提出了一个进化的情况下铸造新的光我们的知识的演变大岛特有的分支。我们发现，马达加斯加现存的树蕨多样性弹簧从三个不同的祖先独立殖民马达加斯加在中新世，这三个单系分支多样化在三个一致的辐射爆发在上新世，达到异常高的多样化率，最有可能响应一个共同的气候触发。因此，最近的多样化爆发可能在现存的马达加斯加雨林生物群落的演变中发挥了重要作用，因此包含了大量年轻的新特有类群。
More than 80% of Madagascar's 12,000 plant species are endemic with the degree of endemism reaching as much as 95% in the scaly tree ferns, an important species rich component of Madagascar's evergreen rainforests. Predominantly African or Asian ancestry and divergence times usually postdating the separation of Madagascar from the Gondwanan landmasses have been demonstrated for several Madagascan animal and angiosperm groups. However, evolutionary studies of rainforest-specific lineages are scarce and the ecological context of radiation events has rarely been investigated. Here, we examine the evolution of Madagascan tree ferns as a rainforest-specific model family, integrate results from bioclimatic niche analysis with a dated phylogenetic framework, and propose an evolutionary scenario casting new light on our knowledge of the evolution of large island endemic clades. We show that Madagascar's extant tree fern diversity springs from three distinct ancestors independently colonizing Madagascar in the Miocene and that these three monophyletic clades diversified in three coincident radiation bursts during the Pliocene, reaching exceptionally high diversification rates and most likely responding to a common climatic trigger. Recent diversification bursts may thus have played a major role in the evolution of the extant Madagascan rainforest biome, which hence contains a significant number of young, neoendemic taxa.