Center for Tropical Research, Institute of the Environment, University of California, Los Angeles, 619 Charles E. Young Dr. South, La Kretz Hall, Suite 300, Los Angeles, CA 90095-1496, USA.
Mol Ecol. 2011 Nov;20(21):4564-76. doi: 10.1111/j.1365-294X.2011.05304.x. Epub 2011 Oct 10.
The Andes are known to have influenced speciation patterns in many taxa, yet whether species diversification occurred simultaneously with their uplift or only after uplift was complete remains unknown. We examined both the phylogenetic pattern and dates of branching in Adelomyia hummingbirds in relation to Andean uplift to determine whether diversification coincides with the chronological phases of the uplift or with recent climatic fluctuations after Andean formation. Results suggest that the genus Adelomyia originated in the central Andes in the Miocene and was found to be comprised of six deeply divergent phylogroups dating between 3.5 and 6 Ma. The most basal splits in the tree, corresponding to the most southerly distributed of the six phylogroups, diverged in the late Miocene, whereas the northern phylogroups originated during the early-to-mid-Pliocene, when the northern Andes reached heights sufficient to support Adelomyia populations. Although we provide evidence for a southern origin for the group, the subsequent diversification of the northern phylogroups did not strictly follow the hypothesized south-to-north orogeny of the Andes. Further genetic structure within phylogroups may have resulted from Pleistocene climate fluctuations after the onset of the six lineages during the Mio-Pliocene. We explore the processes that promoted diversification in the Andes and suggest that in at least some groups, divergence was coupled to Andean orogeny.
安第斯山脉被认为对许多分类群的物种形成模式产生了影响，但物种多样化是与山脉抬升同时发生的，还是在山脉抬升完成后才发生的，目前尚不清楚。我们研究了安第斯山脉蜂鸟 Adelomyia 的系统发育模式和分支时间与安第斯山脉抬升的关系，以确定多样化是否与山脉抬升的时间阶段一致，还是与安第斯山脉形成后最近的气候波动有关。结果表明， Adelomyia 属起源于中新世的安第斯山脉中部，由六个深度分化的谱系组成，其分支时间在 350 万至 600 万年前。树中最基部的分裂，对应于六个谱系中分布最南的谱系，发生在中新世晚期，而北部的谱系起源于上新世早期到中期，当时北安第斯山脉的高度足以支持 Adelomyia 种群。尽管我们提供了该组以南起源的证据，但北部谱系的随后多样化并没有严格遵循安第斯山脉假设的从南到北的造山运动。谱系内进一步的遗传结构可能是由于中新世到上新世期间六个谱系开始后的更新世气候波动造成的。我们探讨了促进安第斯山脉多样化的过程，并认为在至少一些群体中，分化与安第斯造山运动有关。
