The tempo and mode of barnacle evolution
The tempo and mode of barnacle evolution
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DOI：
10.1016/j.ympev.2007.10.004
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发表时间：
2008-01-01
影响因子：
4.1
通讯作者：
Crandall, Keith A.
中科院分区：
文献类型：
--
作者：
Perez-Losada, Marcos;Harp, Margaret;Crandall, Keith A.
以前解决藤壶进化关系的系统发育尝试很少，并且依赖于有限的分类群采样。本文通过对76种胸科动物（内群）和15种根头类动物（外群）中3个核基因（18S、28S和H3）的DNA序列和44个形态特征的分析，探讨了胸科动物藤壶进化的速度和模式。利用最大简约、最大似然和贝叶斯推理的系统发育方法和14个化石校准，我们发现：(1)拟胚属形成一个单系类群；(2)无甲壳的带梗藤壶（异缘形）不是祖先，而是至少两次从有壳形态进化而来的；(3) 5 -> - 6 -> - 8 -> - 12+板的个体发育模式不反映胸壳的演化；(4)传统的不对称藤壶（疣科）和Balanomorpha均为单系藤壶，并共同构成一个单系群；(5)胸科的不对称和花梗缺失经历了两次进化，导致Verrucomorpha和Sessilia都没有形成目前定义的单系类群；(6)鳞片不是单系的；(7)胸亚目自早石炭世（340mya）开始演化，上侏罗统（147mya）为Sessilia的最后一次辐射。因此，这些结果否定了许多关于胸胸卷叶猴特征进化的潜在假设。激发了关于胸腺放射的各种新思想，并建议需要根据估计的系统发育关系对胸腺放射分类进行重大重新安排。(c) 2007爱思唯尔公司版权所有。
Previous phylogenetic attempts at resolving barnacle evolutionary relationships are few and have relied on limited taxon sampling. Here we combine DNA sequences from three nuclear genes (18S, 28S and H3) and 44 morphological characters collected from 76 thoracican (ingroup) and 15 rhizocephalan (outgroup) species representing almost all the Thoracica families to assess the tempo and mode of barnacle evolution. Using phylogenetic methods of maximum parsimony, maximum likelihood, and Bayesian inference and 14 fossil calibrations, we found that: (1) Iblomorpha form a monophyletic group; (2) pedunculated barnacles without shell plates (Heteralepadomorpha) are not ancestral, but have evolved, at least twice, from plated forms; (3) the ontogenetic pattern with 5 -> 6 -> 8 -> 12+ plates does not reflect Thoracica shell evolution; (4) the traditional asymmetric barnacles (Verrucidae) and the Balanomorpha are each monophyletic and together they form a monophyletic group; (5) asymmetry and loss of a peduncle have evolved twice in the Thoracica, resulting in neither the Verrucomorpha nor the Sessilia forming monophyletic groups in their present definitions; (6) the Scalpellomorpha are not monophyletic; (7) the Thoracica suborders evolved since the Early Carboniferous (340 mya) with the final radiation of the Sessilia in the Upper Jurassic (147 mya). These results, therefore, reject many of the underlying hypotheses about character evolution in the Cirripedia Thoracica. stimulate a variety of new thoughts on thoracican radiation, and suggest the need for a major rearrangement in thoracican classification based on estimated phylogenetic relationships. (c) 2007 Elsevier Inc. All rights reserved.