Voelker Gary, Peñalba Joshua V, Huntley Jerry W, Bowie Rauri C K
Department of Wildlife and Fisheries Sciences and Biodiversity Research and Teaching Collections, Texas A&M University, College Station, TX 77843, USA.
Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
Mol Phylogenet Evol. 2014 Apr;73:97-105. doi: 10.1016/j.ympev.2014.01.024. Epub 2014 Feb 4.
Erythropygia scrub-robins and their allies are distributed throughout Africa, Europe, Southeast Asia, India, Madagascar and the Seychelles. This broad distribution, as well as the distribution of Erythropygia taxa across Africa, presents an interesting opportunity to explore the mechanisms by which this biogeographic distribution was achieved. Multilocus sequence data (3310 base pairs from two mitochondrial and two nuclear genes) were generated for all species of Erythropygia and Cercotrichas scrub-robins, as well as from genera previously shown to render Erythropygia paraphyletic. Using model-based phylogenetic methods and molecular clock dating, we constructed a time-calibrated molecular phylogenetic hypothesis for the lineage. Ancestral area reconstructions were performed on the phylogeny using probabilistic approaches implemented in LaGrange and BioGeoBEARS. Our results confirm that Erythropygia is not monophyletic, and that one of the two Erythropygia clades is more closely related to a clade of Asian and Indian Ocean islands distributed species. Overall, the Erythropygia and allies clade originated in Africa in the late Miocene c. 6.9 Ma. Subsequently, a number of overwater dispersals occurred to include an initial colonization of Southeast Asia, and an ensuing progression of colonizations from Southeast Asia to the Seychelles, from there to Madagascar, and from these Indian Ocean islands back to Southeast Asia. Within the two clades of Erythropygia, ancestral area reconstructions within Africa indicate a Southern Africa origin, with subsequent lineage divergence in each clade indicating northward colonization. Overall, this clade of non-migratory songbirds shows a remarkable number of trans-oceanic colonization events, that were possibly facilitated by wind-driven dispersal; repeated Africa to Asia colonizations, two of which occur in this clade, are exceptionally rare in birds. Also rare is our finding that colonization patterns in Africa indicate a southern to northern progression.
红臀灌丛鸫及其近缘种分布于非洲、欧洲、东南亚、印度、马达加斯加和塞舌尔。这种广泛的分布，以及红臀灌丛鸫类群在非洲的分布，为探索这种生物地理分布得以实现的机制提供了一个有趣的机会。我们为所有红臀灌丛鸫和塞氏灌丛鸫物种，以及先前显示会使红臀灌丛鸫成为并系群的属，生成了多位点序列数据（来自两个线粒体基因和两个核基因的3310个碱基对）。使用基于模型的系统发育方法和分子钟定年，我们构建了该谱系的时间校准分子系统发育假说。利用在LaGrange和BioGeoBEARS中实现的概率方法，在系统发育树上进行了祖先区域重建。我们的结果证实，红臀灌丛鸫不是单系的，并且两个红臀灌丛鸫分支之一与一个分布于亚洲和印度洋岛屿的物种分支关系更密切。总体而言，红臀灌丛鸫及其近缘种分支起源于中新世晚期约690万年前的非洲。随后，发生了多次越水扩散，包括最初对东南亚的殖民，以及随后从东南亚到塞舌尔、从塞舌尔到马达加斯加，再从这些印度洋岛屿回到东南亚的一系列殖民过程。在红臀灌丛鸫的两个分支中，非洲内部的祖先区域重建表明起源于南部非洲，每个分支随后的谱系分化表明向北殖民。总体而言，这一非迁徙鸣禽分支显示出大量跨洋殖民事件，这些事件可能是由风驱动的扩散促成的；从非洲到亚洲的反复殖民，其中两次发生在这个分支中，在鸟类中极为罕见。我们的发现同样罕见，即非洲的殖民模式表明是从南向北发展的。
