Systematics and Biodiversity, Göteborg University, Department of Zoology, Box 463, SE-405 30 Göteborg, Sweden.
Mol Phylogenet Evol. 2010 May;55(2):347-57. doi: 10.1016/j.ympev.2009.11.010. Epub 2009 Nov 29.
The phylogeny of 18 taxa in the Lanius excubitor complex, and the related species L. sphenocercus, L. ludovicianus and L. somalicus, was estimated based on the mitochondrial cytochrome b gene and the non-coding D-loop (in total approximately 1.3 kb). According to the mitochondrial gene tree, Lanius excubitor s.l. is non-monophyletic, with some of its subspecies being more closely related to L. sphenocercus, L. ludovicianus, and L. somalicus. Also the division of the L. excubitor complex into a northern (L. excubitor) and a southern (L. meridionalis) species, as has been proposed based on morphological and ecological similarity and geographical distributions, is not compatible with the mitochondrial tree. Overall, genetic divergences among the ingroup taxa are small, indicating a recent radiation. A tree based on the nuclear ornithine decarboxylase (ODC) introns 6-7 is unresolved with respect to the ingroup, but provides strong support for a clade containing the Lanius excubitor complex, L. sphenocercus, L. ludovicianus and L. somalicus. We discuss the incongruence between the current taxonomy and the mitochondrial gene tree, and conclude that based on the latter the Lanius excubitor complex may be treated as at least six species, L. borealis, L. elegans, L. excubitor, L. lahtora, L. meridionalis, and L. uncinatus, but that other taxonomic treatments are also possible. However, uncertainty regarding to which extent the mitochondrial gene tree reflects the species phylogeny prevents us from recommending taxonomic change without further investigation. This study highlights the possible danger of relying on a single molecular marker, such as mitochondrial DNA, in taxonomic revisions and phylogenetic inference.
基于线粒体细胞色素 b 基因和非编码 D 环（总共约 1.3kb），对 18 个蓝矶鸫复合体种及相关种（白喉矶鸫、栗腹矶鸫和索马里矶鸫）进行了系统发育估计。根据线粒体基因树，蓝矶鸫复合体并非单系群，其一些亚种与白喉矶鸫、栗腹矶鸫和索马里矶鸫的亲缘关系更为密切。此外，基于形态学和生态相似性以及地理分布，将蓝矶鸫复合体划分为北方种（蓝矶鸫）和南方种（蓝矶鸫）的观点与线粒体树不一致。总体而言，内类群种间的遗传分歧较小，表明近期辐射。基于核鸟氨酸脱羧酶（ODC）内含子 6-7 的系统发育树在种内没有解决问题，但为包含蓝矶鸫复合体、白喉矶鸫、栗腹矶鸫和索马里矶鸫的一个分支提供了有力支持。我们讨论了当前分类学与线粒体基因树之间的不一致性，并得出结论，基于后者，蓝矶鸫复合体可能被视为至少六个种，即白颊蓝矶鸫、优雅蓝矶鸫、蓝矶鸫、拉脱维亚蓝矶鸫、南方蓝矶鸫和乌灰蓝矶鸫，但也可能存在其他分类处理方法。然而，由于对线粒体基因树在多大程度上反映物种系统发育存在不确定性，我们在没有进一步调查的情况下，无法推荐进行分类学变更。本研究强调了在分类修订和系统发育推断中依赖单一分子标记（如线粒体 DNA）的潜在危险。
