Ribera Ignacio, Vogler Alfried P, Balke Michael
Departamentode Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, José Gutiérrez Abascal 2, Madrid 28006, Spain.
Department of Entomology, Natural History Museum, Cromwell Road, London SW7 5BD, UK.
Cladistics. 2008 Aug;24(4):563-590. doi: 10.1111/j.1096-0031.2007.00192.x. Epub 2008 Feb 16.
Dytiscidae is the most diverse family of beetles in which both adults and larvae are aquatic, with examples of extreme morphological and ecological adaptations. Despite continuous attention from systematists and ecologists, existing phylogenetic hypotheses remain unsatisfactory because of limited taxon sampling or low node support. Here we provide a phylogenetic tree inferred from four gene fragments (cox1, rrnL, H3 and SSU, ≈ 4000 aligned base pairs), including 222 species in 116 of 174 known genera and 25 of 26 tribes. We aligned ribosomal genes prior to tree building with parsimony and Bayesian methods using three approaches: progressive pair-wise alignment with refinement, progressive alignment modeling the evolution of indels, and deletion of hypervariable sites. Results were generally congruent across alignment and tree inference methods. Basal relationships were not well defined, although we identified 28 well supported lineages corresponding to recognized tribes or groups of genera, among which the most prominent novel results were the polyphyly of Dytiscinae; the grouping of Pachydrini with Bidessini, Peschetius with Methlini and Coptotomus within Copelatinae; the monophyly of all Australian Hydroporini (Necterosoma group), and their relationship with the Graptodytes and Deronectes groups plus Hygrotini. We found support for a clade formed by Hydroporinae plus Laccophilini, and their sister relationship with Cybistrini and Copelatinae. The tree provided a framework for the analysis of species diversification in Dytiscidae. We found a positive correlation between the number of species in a lineage and the age of the crown group as estimated through a molecular clock approach, but the correlation with the stem age was non-significant. Imbalances between sister clades were significant for several nodes, but the residuals of the regression of species numbers with the crown age of the group identified only Bidessini and the Coptotomus + Agaporomorphus clade as lineages with, respectively, above and below expected levels of species diversity. © The Willi Hennig Society 2008.
龙虱科是甲虫中多样性最为丰富的一个科，其成虫和幼虫均生活在水中，展现出了极端的形态和生态适应性。尽管分类学家和生态学家持续关注，但由于分类单元采样有限或节点支持率低，现有的系统发育假说仍不尽人意。在此，我们提供了一棵基于四个基因片段（cox1、rrnL、H3和SSU，约4000个比对碱基对）推断出的系统发育树，涵盖了174个已知属中的116个属的222个物种以及26个族中的25个族。在构建系统发育树之前，我们使用三种方法，通过简约法和贝叶斯方法对核糖体基因进行比对：逐步成对比对并优化、逐步比对并对插入缺失的进化进行建模，以及删除高变位点。不同的比对和系统发育树推断方法得出的结果总体一致。尽管我们识别出了28个得到充分支持的谱系，它们分别对应于公认的族或属组，但基部关系并未明确界定。其中最显著的新结果是龙虱亚科的多系性；厚龙虱族与突眼龙虱族的聚类、佩氏龙虱属与梅氏龙虱属的聚类以及突背龙虱属在隐翅龙虱亚科内的聚类；所有澳大利亚沼梭龙虱族（突眼沼梭龙虱组）的单系性，以及它们与刻纹龙虱属和毛眼龙虱属组加上毛跗龙虱族的关系。我们发现支持由沼梭龙虱亚科加毛跗龙虱族形成的一个分支，以及它们与齿缘龙虱族和隐翅龙虱亚科的姐妹关系。该系统发育树为分析龙虱科物种多样化提供了一个框架。我们发现一个谱系中的物种数量与通过分子钟方法估计的冠群年龄之间存在正相关，但与干群年龄的相关性不显著。几个节点的姐妹分支之间的不平衡是显著的，但用冠群年龄对物种数量进行回归分析的残差仅将突眼龙虱族和突背龙虱属 + 异形龙虱属分支确定为物种多样性分别高于和低于预期水平的谱系。© 威利·亨尼希学会2008年。
