The Emergence of Lobsters: Phylogenetic Relationships, Morphological Evolution and Divergence Time Comparisons of an Ancient Group (Decapoda: Achelata, Astacidea, Glypheidea, Polychelida)
The Emergence of Lobsters: Phylogenetic Relationships, Morphological Evolution and Divergence Time Comparisons of an Ancient Group (Decapoda: Achelata, Astacidea, Glypheidea, Polychelida)
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DOI：
10.1093/sysbio/syu008
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发表时间：
2014-07-01
影响因子：
6.5
通讯作者：
Crandall, Keith A.
中科院分区：
文献类型：
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作者：
Bracken-Grissom, Heather D.;Ahyong, Shane T.;Crandall, Keith A.
龙虾是一种普遍存在且具有重要经济意义的十足甲壳类动物，包括下目多螯虾目、螯虾目、螯虾目和螯虾目。它们包括我们熟悉的种类，如带刺的、拖鞋的、有爪的龙虾和小龙虾，以及我们不熟悉的种类，如深海和“活化石”物种。这些次目之间的高度形态多样性导致了动态分类和相互矛盾的进化关系假设。在本研究中，我们利用6个基因（线粒体和细胞核）和195个形态特征对173种龙虾的主要类群和94%的属进行了系统发育关系估计，这是迄今为止最全面的采样。在结合（分子+形态）分析中，龙虾恢复为非单系组合。79个属中有7个属为多系或副系，其余属均为单系。丰富的化石历史加上密集的分类覆盖，使我们能够使用两种截然不同的方法来估计和比较主要谱系的分化时间和起源。年龄先验是根据化石年龄信息或化石发现、年龄和现存物种计数数据构建和/或包含的。两种方法的结果在主要谱系的深层到浅层分类差异上基本一致。最早的龙虾样十足动物（Polychelida）的起源估计在泥盆纪（类似于409-372 Ma），所有的次足动物都出现在石炭纪（类似于354 -318 Ma）。化石校准子采样研究检查了采样密度（化石数量）和放置位置（深、中、浅）对发散时间估计的影响。我们的研究结果表明，在差异定年分析中，每10个操作分类单位（OTUs）至少包括1个化石。[约会;十足类;散度;龙虾;分子;形态;系统发生学。]。
Lobsters are a ubiquitous and economically important group of decapod crustaceans that include the infraorders Polychelida, Glypheidea, Astacidea and Achelata. They include familiar forms such as the spiny, slipper, clawed lobsters and crayfish and unfamiliar forms such as the deep-sea and "living fossil" species. The high degree of morphological diversity among these infraorders has led to a dynamic classification and conflicting hypotheses of evolutionary relationships. In this study, we estimated phylogenetic relationships among the major groups of all lobster families and 94% of the genera using six genes (mitochondrial and nuclear) and 195 morphological characters across 173 species of lobsters for the most comprehensive sampling to date. Lobsters were recovered as a non-monophyletic assemblage in the combined (molecular + morphology) analysis. All families were monophyletic, with the exception of Cambaridae, and 7 of 79 genera were recovered as poly- or paraphyletic. A rich fossil history coupled with dense taxon coverage allowed us to estimate and compare divergence times and origins of major lineages using two drastically different approaches. Age priors were constructed and/or included based on fossil age information or fossil discovery, age, and extant species count data. Results from the two approaches were largely congruent across deep to shallow taxonomic divergences across major lineages. The origin of the first lobster-like decapod (Polychelida) was estimated in the Devonian (similar to 409-372 Ma) with all infraorders present in the Carboniferous (similar to 353-318 Ma). Fossil calibration subsampling studies examined the influence of sampling density (number of fossils) and placement (deep, middle, and shallow) on divergence time estimates. Results from our study suggest including at least 1 fossil per 10 operational taxonomic units (OTUs) in divergence dating analyses. [Dating; decapods; divergence; lobsters; molecular; morphology; phylogenetics.].