Spider phylogenomics: untangling the Spider Tree of Life.
Spider phylogenomics: untangling the Spider Tree of Life.
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作者：
Garrison NL;Rodriguez J;Agnarsson I;Coddington JA;Griswold CE;Hamilton CA;Hedin M;Kocot KM;Ledford JM;Bond JE
蜘蛛(蜘蛛目)是大量的多面手节肢动物捕食者，在地球上几乎每个生态系统中都能找到，已经持续了3.8亿多年。长期以来，蜘蛛一直是研究复杂交配和结网行为、关键创新和适应性辐射假说的进化模型，并一直是通过雌性选择进行性别选择等重要理论的灵感来源。不幸的是，过去重建蜘蛛系统发育的主要尝试通常是使用“通常可疑的”基因，但一直无法为整个目建立一个得到很好支持的系统发育框架。为了进一步解决蜘蛛的进化关系，我们组装了一个基于转录组的数据集，包括70个组内蜘蛛分类群。使用基于最大似然和快捷合并的方法，我们分析了8个数据集，其中最大的包含3398个基因区和696,652个氨基酸位点，形成了迄今为止最大的蜘蛛关系系统学分析。与长期以来认为圆网是蜘蛛进化的最高成就相反，蜘蛛网类型的祖先状态重建支持圆网的系统发育古老起源，多样性分析表明，主要居住在地面、无网的RTA分支的多样化速度快于圆网编织者。与我们在此报告的分子测年估计一致，这可能反映了在1.25亿-9000万年前的白垩纪陆地革命期间，非飞行昆虫的生物量大幅增加，有利于蜘蛛的多样化，这些蜘蛛以卷轴动物为食，而不是飞行的猎物。我们的研究结果对我们理解蜘蛛系统学也有重要意义。系统发育学分析证实了几个被广泛接受的高级类群：背角亚科、大眼蛛亚目、拟天敌亚纲、天牛亚科、蜘蛛亚科、天蛛亚科、蜘蛛亚科、蜘蛛总科、RTA支系、狄奥尼卡亚纲和狼蛛总科。或者，我们的结果挑战了Eresoidae、Orbchoariae和Deinopoidae的单系。蜘蛛目的基本分支--主要的古核状和新核状分支的组成似乎是错误的。传统的单性雌亚科需要修改，因为我们的发现似乎支持新构思的合精纲的概念。丝虫和幼虫的姐妹配对意味着，每个家族的一些特殊特征实际上可能是这两个家族的同形。细线虫现在被认为是线虫亚科的一个可能的姐妹群，说明了在更复杂的线虫生殖器疾病、旋转器官和呼吸器官的进化过程中可能的中间体。
Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the “usual suspect” genes have been unable to produce a well-supported phylogenetic framework for the entire order. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125–90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results challenge the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified. Traditional Haplogynae is in need of revision, as our findings appear to support the newly conceived concept of Synspermiata. The sister pairing of filistatids with hypochilids implies that some peculiar features of each family may in fact be synapomorphic for the pair. Leptonetids now are seen as a possible sister group to the Entelegynae, illustrating possible intermediates in the evolution of the more complex entelegyne genitalic condition, spinning organs and respiratory organs.