A Phylogenomic Approach to Resolve the Arthropod Tree of Life
A Phylogenomic Approach to Resolve the Arthropod Tree of Life
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DOI：
10.1093/molbev/msq130
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发表时间：
2010-11-01
影响因子：
10.7
通讯作者：
Misof, Bernhard
中科院分区：
文献类型：
--
作者：
Meusemann, Karen;von Reumont, Bjoern M.;Misof, Bernhard
节肢动物是最早征服陆地和空气的动物。它们涵盖了所描述的所有现存物种的四分之三以上。这一非凡的进化成功是基于一系列令人震惊的高度适应性的身体组织。然而，缺乏强有力的系统发育关系，目前阻碍了对潜在进化过程的可靠重建。在这里，我们表明，系统基因组数据可以极大地促进我们对节肢动物进化的理解，并解决现有假说之间的几个冲突。我们组装了一个由233个分类群和775个基因组成的数据集，最终使用新的启发式算法从其中选择了包含117个分类群和129个基因的最佳信息量数据集，并与未简化的数据集进行了比较。我们收录了11个物种的新表达序列标签(EST)数据，以及所有已发表的系统基因组数据，这些数据由最近发表的具有重要分类学意义的节肢动物分类群的EST数据补充。这种彻底的抽样减少了由于抽样不足的分类群和基因的随机效应而获得虚假结果的机会。建立了基因的正交学预测、比对掩蔽工具，以及使用新的启发式方法选择由于平衡的分类-基因比率而获得的最具信息量的基因。我们优化的数据集有力地解决了主要节肢动物之间的关系。我们得到了对指甲类和真节肢动物姐妹群关系的大力支持，也得到了对迟滞类和环状神经类密切联系的强烈支持。在泛甲壳类中，我们的分析产生了副甲壳类和单系六足类，并有力地解析了单系内翅目昆虫。然而，我们的分析也显示了最近被认为已经解决的几个深分裂，例如，多足类的位置，对分析方法具有显著的敏感性。
Arthropods were the first animals to conquer land and air. They encompass more than three quarters of all described living species. This extraordinary evolutionary success is based on an astoundingly wide array of highly adaptive body organizations. A lack of robustly resolved phylogenetic relationships, however, currently impedes the reliable reconstruction of the underlying evolutionary processes. Here, we show that phylogenomic data can substantially advance our understanding of arthropod evolution and resolve several conflicts among existing hypotheses. We assembled a data set of 233 taxa and 775 genes from which an optimally informative data set of 117 taxa and 129 genes was finally selected using new heuristics and compared with the unreduced data set. We included novel expressed sequence tag (EST) data for 11 species and all published phylogenomic data augmented by recently published EST data on taxonomically important arthropod taxa. This thorough sampling reduces the chance of obtaining spurious results due to stochastic effects of undersampling taxa and genes. Orthology prediction of genes, alignment masking tools, and selection of most informative genes due to a balanced taxa-gene ratio using new heuristics were established. Our optimized data set robustly resolves major arthropod relationships. We received strong support for a sister group relationship of onychophorans and euarthropods and strong support for a close association of tardigrades and cycloneuralia. Within pancrustaceans, our analyses yielded paraphyletic crustaceans and monophyletic hexapods and robustly resolved monophyletic endopterygote insects. However, our analyses also showed for few deep splits that were recently thought to be resolved, for example, the position of myriapods, a remarkable sensitivity to methods of analyses.