The Causes of Evolutionary Radiations in Archipelagoes: Passerine Birds in the Lesser Antilles
The Causes of Evolutionary Radiations in Archipelagoes: Passerine Birds in the Lesser Antilles
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群岛进化辐射的原因：小安的列斯群岛的雀形目鸟类
DOI：
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发表时间：
2007
影响因子：
2.9
通讯作者：
E. Bermingham
中科院分区：
文献类型：
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作者：
R. Ricklefs;E. Bermingham
为了探究为何某些谱系会发生进化辐射，我们将夏威夷和加拉帕戈斯群岛（这两个群岛都有著名的鸟类辐射现象）的雀形目鸟类区系与小安的列斯群岛（没有这种现象）的雀形目鸟类区系进行了比较。我们重点关注通过异域物种形成和二次同域分布来积累多样性所需的四个步骤：隔离状态下的遗传分化、岛屿种群的持续存在、源岛屿的重新定殖以及二次同域分布时的生态相容性。对小安的列斯群岛岛屿种群间遗传分化的分析显示，既有长期独立进化的证据，也有分化的岛屿种群在群岛中重新扩张的证据，但几乎没有不同遗传谱系二次同域分布的证据。来自大陆或附近大岛源地的高定殖率的群岛可能无法促进进化辐射，因为定殖者占据了生态空间，并通过竞争限制了多样化。然而，形态学分析表明，夏威夷、加拉帕戈斯和小安的列斯群岛的异域种群在物种间的分化相似，尽管在夏威夷和加拉帕戈斯，二次同域分布物种间的分化速度明显更快。或者，夏威夷和加拉帕戈斯相对没有病原体，这可能促进了当地多样性的积累，否则由于疾病介导的竞争，种群的二次同域分布可能会受到阻碍。
To investigate why some lineages undergo evolutionary radiation, we compare the passerine avifaunas of the Hawaiian and Galápagos archipelagoes, which have supported well‐known radiations of birds, with those of the Lesser Antilles, which have not. We focus on four steps required for the buildup of diversity through allopatric speciation and secondary sympatry: genetic divergence in isolation, persistence of island populations, recolonization of source islands, and ecological compatibility in secondary sympatry. Analysis of genetic divergence among island populations in the Lesser Antilles reveals evidence of both prolonged independent evolution and re‐expansion of differentiated island populations through the archipelago but little evidence of secondary sympatry of divergent genetic lineages. Archipelagoes with high rates of colonization from continental or nearby large‐island sources might fail to promote evolutionary radiations because colonists fill ecological space and constrain diversification through competition. However, morphological analysis demonstrated similar divergence between allopatric populations in species in Hawaii, Galápagos, and the Lesser Antilles, although the rate of divergence between secondarily sympatric species evidently is more rapid in Hawaii and the Galápagos. Alternatively, endemic buildup of diversity might be facilitated by the relative absence of pathogens in Hawaii and Galápagos that otherwise could prevent the secondary sympatry of populations owing to disease‐mediated competition.