Molecular phylogenetic analyses of crustaceans

该项目将提供优先方案1174中推断的后生动物发生所需的甲壳类分类群的序列数据。经过四年的数据采集，主要目标是了解在系统发育树中产生错误的数据分析方法中隐含的比对模式和假设。我们要评估现有的证据来支持节肢动物树的Curstacea部分的分支。目前重建的系统发育关系和内甲壳动物仍然是非常竞争和分歧。在这个项目中，我们想测试Entomostraca的单系性，Maxillopoda的概念，Thecostraca的单系性，Mystacocarida，Remipedia，Ceoparida和Malacostraca的位置，Thoracopoda的概念，Palliata假设。在与其他小组合作，我们想推断昆虫纲或Tracheata的确切位置，考虑昆虫，多足类，甲壳类和螯形动物类群的数据。我们负责甲壳类动物的数据。因此，有两个层次的分析：在单一项目内（甲壳纲内的节肢动物发生学）和在优先方案内（节肢动物发生学）。在最后一个资助期间，我们特别希望使用454序列技术添加仍然缺失的Remipedia，Mystacocarida，Ceoparida和Pentastomida的数据。应用复杂的替代模型（特别是考虑到时间异质性）改进了我们的分析，但仍然出现了伪影。最困难的任务是发现假分支支持和隐藏的长分支的影响。在与协调项目的密切合作中，我们将使用新的工具来分析比对模式，以有助于更好地了解动物的生殖发育。

This project will contribute sequence data of crustacean taxa that are required for the metazoan phylogeny that is being inferred in the Priority Programme 1174. After four years of data acquisition the main goal is to understand alignment patterns and assumptions implied in data analyses methods that produce errors in phylogenetic trees. We want to evaluate available evidence to support clades in the Curstacea part of the arthropod tree. The current reconstructions of phylogenetic relationships of and within the Crustacea are still very competing and diverging. Within the project we want to test the monophyly of Entomostraca, the Maxillopoda concept, the monophyly of Thecostraca, the position of Mystacocarida, Remipedia, Cephalocarida and Malacostraca, the Thoracopoda concept, the Palliata hypothesis. In cooperation with other groups we want to infer the exact position of the Insecta or Tracheata considering data from insects, myriapods, crustaceans and chelicerate taxa. We are responsible for the crustacean data. Therefore there are two levels of analyses: Within the single project (phylogeny within Crustacea) and within the Priority Programme (arthropod phylogeny). In the last funding period we want especially add data for the still missing Remipedia, Mystacocarida, Cephalocarida, and Pentastomida, using the 454 sequence technology. Applications of complex substitution models (especially allowing for time-heterogeneity) improved our analyses, but nevertheless artefacts still appear. The most difficult task is to discover false clade support and effects of hidden long branches. In close cooperation with the coordination project we will use new tools for analyses of alignment patterns to contribute to a better understanding of animal phylogeny.