Deep Metazoan Phylogeny: Diploblastic Animals

了解双裂门的系统发育和进化对重建动物生命的起源和多样化至关重要。在后生动物进化的基础上，一般认为有四个门：Placozoa、Cnidaria、Porifera和Ctenophora。一个多世纪以来，这些双胚层门之间的系统发育关系、门内的类水平关系、原生动物祖先和高等（三胚层）动物的分离一直是有争议的讨论主题。我们试图生成和分析各种分子标记，以解决基础后生动物的深层系统发育关系（Porifera将被排除在外，因为这些数据是由两个合作小组生成的）。Placozoa， Cnidaria和Ctenophora的所有纲和目的代表和广泛的分子标记将被分析。很明显，后生动物生命之树的基础不能仅仅通过分子序列标记来解决，我们还将包括形态学、rRNA分子形态学、线粒体基因组和antp类基因的基因组组织的特征。在第三个也是最后一个阶段，我们寻求完成数据集，执行串联分析并解决串联数据集中字符权重的关键问题。最终，这项研究旨在为DFG优先计划“深层后生动物系统发育”生成的后生动物生命树提供根源。

Knowledge of the phylogeny and evolution of the diploblast phyla is critical for reconstructing the origin and diversification of animal life. At the base of metazoan evolution four phyla are generally accepted, Placozoa, Cnidaria, Porifera, and Ctenophora. Phylogenetic relationships between these diploblast phyla, class-level relationships within phyla, the protozoan ancestor and the split off of higher (triploblastic) animals have been subject of controversial discussion for more than a century. We seek to generate and analyze a variety of molecular markers to resolve deep phylogenetic relationships in basal metazoans (Porifera will be excluded, since these data are generated by two collaborating groups). Representatives from all classes and orders of Placozoa, Cnidaria, and Ctenophora and a broad spectrum of molecular markers will be analyzed. It has become clear that the base of the metazoan Tree of Life cannot be resolved by molecular sequence markers only and we will also include characters from morphology, rRNA molecule morphology, mitochondrial genomes, and the genomic organization of Antp-class genes. In the third and final period we seek to complete data sets, perform concatenated analyses and address the critical issue of character weighting in a concatenated data set. Eventually this study is meant to provide the root for the metazoan tree of life generated by the DFG priority program “Deep Metazoan Phylogeny”.