Molecular phylogenetic analyses of crustaceans

该项目将提供优先方案1174中正在推断的后生动物系统发展所需的甲壳类分类的序列数据。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所隐含的比对模式和假设。我们想要评估现有的证据，以支持在节肢动物树的Curstacea部分分支。目前对甲壳动物及其内部的系统发育关系的重建仍然是非常竞争和分歧的。在这个项目中，我们想要测试昆虫纲、长足目概念、膜足目单系、重足纲、头足纲和软脚亚纲的位置、胸足纲概念、翼足目假说。在与其他小组的合作中，我们希望根据昆虫、多足类、甲壳类和螯合类的数据来推断昆虫纲或管形目的确切位置。我们要对甲壳类动物的数据负责。因此，有两个层次的分析：在单一项目内(甲壳类内的系统发育)和在优先方案内(节肢动物系统发育)。在上一个资助期，我们特别希望使用454测序技术，为仍然缺失的雷米足纲、水母纲、头壳纲和五角纲增加数据。复杂替代模型的应用(特别是考虑到时间的异质性)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虚假的枝条支撑和隐藏的长树枝的影响。在与协调项目的密切合作下，我们将使用新的工具分析比对模式，以帮助更好地了解动物的系统发育。

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.