Extensive in situ radiation of feather lice on tinamous

Tinamous host the highest generic diversity of lice of any group of birds, as well as hosting representatives of all four avian feather louse ecomorphs. Although the generic diversity of tinamou feather lice is well documented, few attempts have been made to reconstruct the phylogenetic relationships among these lice. To test whether tinamou feather lice form a monophyletic group as a whole, we used whole genome sequencing to estimate a higher-level phylogeny of tinamou feather lice, together with a broad diversity of other avian feather louse groups. In total, we analyzed sequences from over 1000 genes for 48 genera of avian lice using both concatenated and coalescent approaches to estimate the phylogeny of this diverse group of avian feather lice. Although the body louse ecomorph of tinamou feather lice formed a monophyletic group, they did not strictly form a monophyletic group together with the other three ecomorphs of tinamou feather lice. In particular, a clade comprised of several feather louse genera, mainly from South America, are nested phylogenetically within tinamou lice, which also have their main center of diversity in South America. These results suggest in situ radiation of these parasites in South America.

䳍（Tinamous）所寄生的虱类属多样性在所有鸟类类群中位列第一，同时还涵盖了全部4种鸟类羽虱生态型（avian feather louse ecomorphs）的代表类群。尽管䳍羽虱的属多样性已有充分记载，但目前针对该类虱类的系统发育关系重建研究仍较为有限。为验证䳍羽虱整体是否构成一个单系群（monophyletic group），本研究采用全基因组测序（whole genome sequencing）技术，对䳍羽虱及其他多种鸟类羽虱类群开展高阶系统发育树推断。研究总计针对48个鸟类虱类属的逾1000个基因序列，同时采用联配拼接法（concatenated approaches）与溯祖分析法（coalescent approaches）来估算该多样鸟类羽虱类群的系统发育关系。结果显示，䳍羽虱中的体虱生态型类群确实形成了单系群，但该类群与䳍羽虱其余三类生态型并未严格构成统一的单系群。尤为值得注意的是，一个主要由南美地区多个羽虱属组成的演化支（clade），在系统发育层面嵌入于䳍羽虱类群之中——而䳍羽虱的主要多样性分布中心同样位于南美地区。上述结果表明，这类寄生物在南美地区发生了原地辐射演化。