How the Worm Got its Pharynx: Phylogeny, Classification and Bayesian Assessment of Character Evolution in Acoela
How the Worm Got its Pharynx: Phylogeny, Classification and Bayesian Assessment of Character Evolution in Acoela
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DOI：
10.1093/sysbio/syr073
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发表时间：
2011-12-01
影响因子：
6.5
通讯作者：
Raikova, Olga I.
中科院分区：
文献类型：
--
作者：
Jondelius, Ulf;Wallberg, Andreas;Raikova, Olga I.
无腔虫是海洋中的微型蠕虫，目前被认为是所有其他两侧对称动物的姐妹分类群。无体腔长期以来一直被用作进化情景中的模型，并且关于无体腔和两侧祖先特征的一般性结论经常从单个无体腔物种的研究中得出。无体腔类的系统发育研究较少，380种无体腔类的分类比较混乱。在这里，我们使用两个核核糖体基因和一个线粒体基因，结合37个形态特征的分析126个acoel终端（约三分之一的描述种），估计的生殖系统发育和性状进化的Acoela。我们提出了一个估计的后验概率的祖先字符状态在31个控制节点的遗传。基于字符状态的后验分布的形状的总体重建信号被计算用于所有形态学字符和控制节点，以评估这些被重建的程度。体壁肌肉组织比生殖器官重建得更清楚。根的后验相似性通过对所有形态特征的节点和根的后验分布之间的分歧进行平均来计算。Diopisthoporidae是所有其他体腔的姐妹群，与根的后部相似性最高。旋花科，包括几个“模式”的珊瑚，是最分歧的。最后，我们提出了一个系统发育分类的Acoela下降到家庭的水平，以前的6个家庭水平的分类群synchronized。
Acoela are marine microscopic worms currently thought to be the sister taxon of all other bilaterians. Acoels have long been used as models in evolutionary scenarios, and generalized conclusions about acoel and bilaterian ancestral features are frequently drawn from studies of single acoel species. There is no extensive phylogenetic study of Acoela and the taxonomy of the 380 species is chaotic. Here we use two nuclear ribosomal genes and one mitochondrial gene in combination with 37 morphological characters in an analysis of 126 acoel terminals (about one-third of the described species) to estimate the phylogeny and character evolution of Acoela. We present an estimate of posterior probabilities for ancestral character states at 31 control nodes in the phylogeny. The overall reconstruction signal based on the shape of the posterior distribution of character states was computed for all morphological characters and control nodes to assess how well these were reconstructed. The body-wall musculature appears more clearly reconstructed than the reproductive organs. Posterior similarity to the root was calculated by averaging the divergence between the posterior distributions at the nodes and the root over all morphological characters. Diopisthoporidae is the sister group to all other acoels and has the highest posterior similarity to the root. Convolutidae, including several "model" acoels, is most divergent. Finally, we present a phylogenetic classification of Acoela down to the family level where six previous family level taxa are synonymized.