Polychaeta, Annelida, and Articulata are not monophyletic: articulating the Metameria (Metazoa, Coelomata)
Polychaeta, Annelida, and Articulata are not monophyletic: articulating the Metameria (Metazoa, Coelomata)
复制标题
DOI：
10.1590/s0101-81752003000100006
复制
发表时间：
2003-03-01
期刊：
影响因子：
--
通讯作者：
Silva, Gustavo Sene
中科院分区：
文献类型：
--
作者：
Almeida, Waltécio de Oliveira;Christoffersen, Martin Lindsey;Silva, Gustavo Sene
多毛纲是一种具有副足、毛和颈部器官的同色异谱蠕虫。一些作者将环节动物的范围扩大到包括须毛目、Echiura和Clitellata。这些建议不足以产生一个单系群。他们没有考虑到两个非常大的和重要的分支，在一个分支分析在一个更高的水平被证明是嵌套在环节动物：蜕皮动物（节肢动物和相关类群）和肠腔动物（后口动物和相关类群）。后生动物门中大多数特征的进化历史仍然知之甚少。本文对多毛类的内类群进行了系统发育分析，包括作为末端类群的黏虫门（Clitellata）、肠腔虫门（Enterocoela）和蜕皮虫门（Ecdysozoa），其余的非同变异构门（Platyhelminthes）、纽形动物门（Nemertea）、软体动物门（Mollusca）、和星虫属植物被包括在内，以使该树扎根于两侧。从文献中获得经验数据，并用软件Hennig 86运行，对初级同源性的先验假设进行两种比较解释：一种是负特征（编码损失）和另一个只考虑积极的字符最相关的结论是：（1）环节动物和多毛类是非单系的，即使包括Echiura，Clitellata和Pogonophora;（2）传统上被划分为环节动物门和节肢动物门的关节动物门也不是单系的;（3）只有在传统的环节动物分类群之外加入了蜕皮动物门和肠腔动物门时，才能将同科动物变为单系的;（4）蜕皮动物门是无足动物门的姐妹群;（5）有片动物门与沉积物摄食的定居性多毛类有关（6）Owenia + Enterocoela与管栖多毛类形成一个单系群。
Polychaetes are metameric worms recognized for having parapodia, chaetae, and nuchal organs. Some authors have extended the Annelida to include Pogonophora, Echiura, and Clitellata. These suggestions are insufficient to generate a monophyletic group. They do not take into account two very large and important clades that in a cladistic analysis at a higher level are shown to be nested within the Annelida: the Ecdysozoa (arthropods and related taxa) and Enterocoela (deuterostomes and related taxa). Evolutionary histories of most characters across metazoan phyla are still very poorly known. Metameres and coeloms have been considered homoplastic in the literature, and yet the homeobox genes responsible for the expression of metamerism and of paired appendages, at least, are very largely distributed among the Metazoa.A phylogenetic analysis was performed for the ingroups of Polychaeta, including Clitellata, Enterocoela, and Ecdysozoa as terminal taxa.The remaining non-metameric phyla Platyhelminthes,Nemertea,Mollusca,and Sipuncula were included to root the tree within the Bilateria. Empirical data was obtained from the literature and run with the software Hennig86 with two comparative interpretations of a priori hypotheses of primary homology: one with negative characters (coding losses) and another considering only positive characters (without assumptions about losses).The most relevant conclusions are: (1) Annelida and Polychaeta are non-monophyletic,even when including Echiura,Clitellata,and Pogonophora; (2) Articulata, as traditionally circumscribed for Annelida and Arthropoda, is also not monophyletic; (3) Metameria becomes monophyletic only when Ecdysozoa and Enterocoela are included in addition to the traditional annelid taxa; (4) Ecdysozoa are the sister group of Aphrodita; (5) Clitellata are related to deposit-feeding sedentary polychaetes (scolecids), and Questidae represent their sister group;(6) Owenia plus Enterocoela form a monophyletic group related to the tubicolous polychaetes.