Phylogenetic relationships of spatangoid sea urchins (Echinoidea): taxon sampling density and congruence between morphological and molecular estimates
Phylogenetic relationships of spatangoid sea urchins (Echinoidea): taxon sampling density and congruence between morphological and molecular estimates
复制标题
Spatangoid 海胆（Echinoidea）的系统发育关系：分类单元采样密度以及形态和分子估计之间的一致性
DOI：
--
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Jacqueline Mackenzie
中科院分区：
文献类型：
--
作者：
B. Stockley;A. Smith;T. Littlewood;H. Lessios;Jacqueline Mackenzie
使用来自三个基因的数据构建了21种spatangoid海胆的遗传学，并将结果与相同类群和88个最近和化石类群的更大样本的基于形态学的遗传学进行了比较。不同的数据集和分析方法产生不同的系统发育假说，虽然一致性测试表明，所有的分子方法产生的树是一致的。相比之下，从形态学数据产生的树木显着不同，根据分类群的采样密度，只有那些密集的采样（后验加权）是一致的分子估计。在有限的分类单元采样下，深水分类单元中的次级反转被解释为近形，将它们拉到基部位置。化石分类群及其独特的特征组合的增加揭示了隐藏的同源性，并产生了与分子估计相容的同源性。由于在棘突试验中发现不同解剖结构之间的同源性水平大致相似，因此没有一套形态特征可以被认为提供更可靠的系统发育信息。一些传统的分组得到支持，包括在Micrasterina内的Loveniidae，Eschasidae和Spatangidae的分组，但Asterostomatidae被证明是多系的，其成员分散在至少五个不同的分支中。由于这些大多是深海类群，这一发现意味着多个独立的入侵深海。
A phylogeny for 21 species of spatangoid sea urchins is constructed using data from three genes and results compared with morphology‐based phylogenies derived for the same taxa and for a much larger sample of 88 Recent and fossil taxa. Different data sets and methods of analysis generate different phylogenetic hypotheses, although congruence tests show that all molecular approaches produce trees that are congruent with each other. By contrast, the trees generated from morphological data differ significantly according to taxon sampling density and only those with dense sampling (after a posteriori weighting) are congruent with molecular estimates. With limited taxon sampling, secondary reversals in deep‐water taxa are interpreted as plesiomorphies, pulling them to a basal position. The addition of fossil taxa with their unique character combinations reveals hidden homoplasy and generates a phylogeny that is compatible with molecular estimates. As homoplasy levels were found to be broadly similar across different anatomical structures in the echinoid test, no one suite of morphological characters can be considered to provide more reliable phylogenetic information. Some traditional groupings are supported, including the grouping of Loveniidae, Brissidae and Spatangidae within the Micrasterina, but the Asterostomatidae is shown to be polyphyletic with members scattered amongst at least five different clades. As these are mostly deep‐sea taxa, this finding implies multiple independent invasions into the deep sea.