Data from: Out of the Andes: patterns of diversification in clearwing butterflies

Global biodiversity peaks in the tropical forests of the Andes, a striking geological feature that has likely been instrumental in generating biodiversity by providing opportunities for both vicariant and ecological speciation. However, the role of these mountains in the diversification of insects, which dominate biodiversity, has been poorly explored using phylogenetic methods. Here we study the role of the Andes in the evolution of a diverse Neotropical insect group, the clearwing butterflies. We used dated species-level phylogenies to investigate the time-course of speciation and to infer ancestral elevation ranges for two diverse genera. We show that both genera likely originated at middle elevations in the Andes in the Middle Miocene, contrasting with most published results in vertebrates that point to a lowland origin. Although we detected a signature of vicariance caused by the uplift of the Andes at the Miocene-Pliocene boundary, most sister species were parapatric without any obvious vicariant barrier. Combined with an overall decelerating speciation rate, these results suggest an important role for ecological speciation and adaptive radiation, rather than simple vicariance.

全球生物多样性的峰值出现在安第斯（Andes）热带森林中，这一引人注目的地质构造很可能通过为异域成种（vicariant speciation）与生态成种（ecological speciation）提供演化机遇，在生物多样性的形成过程中发挥了关键作用。然而，这类山脉对于构成生物多样性主体的昆虫类群演化分化的作用，却鲜有基于系统发育方法的探索性研究。本研究探讨了安第斯山脉在一类物种丰富的新热带区昆虫类群——透翅蝶的演化过程中所发挥的作用。我们借助带有时间标定的物种级系统发育树，探究物种形成的时间进程，并推断两个物种丰富属的祖先海拔分布范围。研究结果显示，这两个属均可能于中新世中期起源于安第斯山脉的中海拔区域，这与多数已发表的脊椎动物研究得出的“低地起源”结论形成鲜明反差。尽管我们检测到了中新世-上新世交界期安第斯山脉隆升所引发的异域分化信号，但绝大多数姊妹物种均呈邻域分布，未发现明显的异域阻隔屏障。结合整体呈减速趋势的物种形成速率，上述结果表明生态成种与适应辐射在该类群的演化中发挥了重要作用，而非单纯的异域成种过程。