Molecular phylogenetic analyses of crustaceans

该项目将提供甲壳类分类群的序列数据，这些数据是在第1174优先规划中推断的后生动物系统发育所必需的。经过四年的数据采集，主要目标是理解在系统发育树中产生错误的数据分析方法中隐含的对齐模式和假设。我们想要评估现有的证据，以支持节肢动物树中马甲部分的分支。目前对甲壳类动物系统发育关系的重建仍然存在着激烈的竞争和分歧。在这个项目中，我们想要测试昆虫纲的单系性、颌足纲的概念、腹足纲的单系性、密足纲、米足纲、头足纲和腹足纲的位置、胸足纲的概念、Palliata假说。在与其他研究小组的合作中，我们希望根据昆虫、多足类动物、甲壳类动物和螯合动物分类群的数据推断出昆虫亚或气管亚的确切位置。我们负责甲壳类动物的数据。因此，有两个层次的分析：在单个项目（甲壳类动物的系统发育）和在优先项目（节肢动物的系统发育）中。在上一个资助期，我们特别希望使用454序列技术为仍然缺失的Remipedia、Mystacocarida、Cephalocarida和Pentastomida添加数据。复杂替代模型的应用（特别是允许时间异质性）改进了我们的分析，但是仍然出现了人工制品。最困难的任务是发现假枝支撑和隐藏长枝的影响。通过与协调项目的密切合作，我们将使用新的工具来分析排列模式，从而更好地理解动物的系统发育。

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.