University Museum of Bergen, P.O. Box 7800, 5007, Bergen, Norway.
Mol Ecol. 2015 Jan;24(1):180-91. doi: 10.1111/mec.13008. Epub 2014 Dec 3.
A common challenge in phylogenetic reconstruction is to find enough suitable genomic markers to reliably trace splitting events with short internodes. Here, we present phylogenetic analyses based on genomewide single-nucleotide polymorphisms (SNPs) of an enigmatic avian radiation, the subspecies complex of Afrocanarian blue tits (Cyanistes teneriffae). The two sister species, the Eurasian blue tit (Cyanistes caeruleus) and the azure tit (Cyanistes cyanus), constituted the out-group. We generated a large data set of SNPs for analysis of population structure and phylogeny. We also adapted our protocol to utilize degraded DNA from old museum skins from Libya. We found strong population structuring that largely confirmed subspecies monophyly and constructed a coalescent-based phylogeny with full support at all major nodes. The results are consistent with a recent hypothesis that La Palma and Libya are relic populations of an ancient Afrocanarian blue tit, although a small data set for Libya could not resolve its position relative to La Palma. The birds on the eastern islands of Fuerteventura and Lanzarote are similar to those in Morocco. Together they constitute the sister group to the clade containing the other Canary Islands (except La Palma), in which El Hierro is sister to the three central islands. Hence, extant Canary Islands populations seem to originate from multiple independent colonization events. We also found population divergences in a key reproductive trait, viz. sperm length, which may constitute reproductive barriers between certain populations. We recommend a taxonomic revision of this polytypic species, where several subspecies should qualify for species rank.
系统发育重建的一个常见挑战是找到足够多的合适基因组标记，以可靠地追踪具有短节间的分裂事件。在这里，我们展示了基于神秘鸟类辐射——非洲加那利蓝雀亚种复合体的全基因组单核苷酸多态性（SNP）的系统发育分析。两个姐妹物种，欧亚大陆蓝山雀（Cyanistes caeruleus）和蓝腹山雀（Cyanistes cyanus），构成了外群。我们生成了大量 SNP 数据来分析种群结构和系统发育。我们还调整了我们的方案，以利用来自利比亚的旧博物馆皮的降解 DNA。我们发现了强烈的种群结构，这在很大程度上证实了亚种的单系性，并构建了一个基于合并的系统发育树，所有主要节点都得到了充分支持。这些结果与最近的一个假设一致，即拉帕尔马和利比亚是古老非洲加那利蓝雀的残余种群，尽管利比亚的数据集很小，无法确定其相对于拉帕尔马的位置。富埃特文图拉岛和兰萨罗特岛上的鸟类与摩洛哥的鸟类相似。它们共同构成了一个包含其他加那利群岛（除拉帕尔马岛外）的分支的姐妹群，其中埃尔希罗岛是三个中心岛屿的姐妹群。因此，现存的加那利群岛种群似乎起源于多次独立的殖民事件。我们还在一个关键的繁殖特征——精子长度上发现了种群分歧，这可能构成了某些种群之间的繁殖障碍。我们建议对这个多型种进行分类学修订，其中几个亚种应该有资格成为独立的物种。
