Lee P L, Clayton D H, Griffiths R, Page R D
Department of Zoology, University of Oxford, United Kingdom.
Proc Natl Acad Sci U S A. 1996 Jul 9;93(14):7091-6. doi: 10.1073/pnas.93.14.7091.
Swiftlets are small insectivorous birds, many of which nest in caves and are known to echolocate. Due to a lack of distinguishing morphological characters, the taxonomy of swiftlets is primarily based on the presence or absence of echolocating ability, together with nest characters. To test the reliability of these behavioral characters, we constructed an independent phylogeny using cytochrome b mitochondrial DNA sequences from swiftlets and their relatives. This phylogeny is broadly consistent with the higher classification of swifts but does not support the monophyly of swiftlets. Echolocating swiftlets (Aerodramus) and the nonecholocating "giant swiftlet" (Hydrochous gigas) group together, but the remaining nonecholocating swiftlets belonging to Collocalia are not sister taxa to these swiftlets. While echolocation may be a synapomorphy of Aerodramus (perhaps secondarily lost in Hydrochous), no character of Aerodramus nests showed a statistically significant fit to the molecular phylogeny, indicating that nest characters are not phylogenetically reliable in this group.
金丝燕是小型食虫鸟类，其中许多在洞穴中筑巢，并且已知具有回声定位能力。由于缺乏明显的形态特征，金丝燕的分类主要基于回声定位能力的有无以及巢穴特征。为了测试这些行为特征的可靠性，我们利用金丝燕及其近缘物种的细胞色素b线粒体DNA序列构建了一个独立的系统发育树。这个系统发育树与雨燕的高级分类大致一致，但不支持金丝燕的单系性。具有回声定位能力的金丝燕（Aerodramus）和不具有回声定位能力的“大型金丝燕”（Hydrochous gigas）聚在一起，但其余属于Collocalia属的不具有回声定位能力的金丝燕并非这些金丝燕的姐妹类群。虽然回声定位可能是Aerodramus属的一个共衍征（也许在Hydrochous属中是次生丧失的），但Aerodramus属巢穴的任何特征都未显示出与分子系统发育有统计学上的显著契合，这表明巢穴特征在该类群中在系统发育上并不可靠。
