Systematics and Evolution of Pedipalpi (Whip Spiders and Whip Scorpions): Phylogenomics and Morphology of Understudied Arachnids

Pedipalpi是一个由三个鲜为人知的类群组成的谱系：Amblypygi（鞭蛛），Schizomida（短尾鞭蝎或微鞭蝎）和Thelyphonida（鞭蝎或鞭蝎）。这些夜间捕食者生活在除南极洲以外的所有主要陆地上的热带和亚热带栖息地，对控制昆虫数量很重要，在3亿年内解剖学上几乎没有改变。关于它们的生活史和行为所知甚少，揭示了复杂的求偶仪式、雄性战斗、领土争夺、社会性、亲代照顾和带有有毒防御分泌物的化学防御。尽管Pedipalpi具有深远的进化时间尺度、全球分布、生态重要性和迷人的生活史和行为，但一个世纪以来，对它们的分类几乎没有取得任何进展，它们在生命之树中的分支几乎没有组装起来，阻碍了对其进化假设的检验。通过利用基因组学、显微镜学、成像和信息学方面的技术进步，并整合解剖学和基因组数据，该项目将建立第一个完整的活体和化石Pedipalpi生命树，培训新一代研究这些研究不足的蛛形纲动物的专家，并向公众传播研究结果。来自科学界代表性不足群体的两名博士生和两名博士后助理将得到支持。每年，一名本科生、两名高中生和两名公民科学家将参与研究。本课程将在四大洲举办，内容包括小足猴的生物学和分类，以及当地动物群的介绍。新的材料、数据和图像将加强科学基础设施。结果、数据和教育推广材料将在会议上、网上和通过全国分发的课堂杂志传播。该项目有四个主要目标。(1)采用高通量、靶向富集方法，每个标本将产生约100,000个碱基对的DNA序列，用于代表所有主要谱系，70%的属和30%的现存Pedipalpi物种。(2)对基因组数据集中的所有物种和已灭绝谱系及其螯合亲缘的代表进行形态学观察。系统发育学和形态学研究将用于(3)提出一种属以上的预测分类，并对4个谱系进行专题分类修订；(4)研究有关马掌的进化和多样化的问题。Pedipalpi的主要谱系是如何、何时、在哪里多样化的，哪些关键的创新使它们能够做到这一点？穴居动物（Pedipalpi）通常居住在洞穴中，而洞穴生物的形态专门化是不可逆转的进化死胡同吗？两性二态性是跛足动物的棘肢（爪）的祖先还是衍生，它的进化是为了减少在仪仪化的雄性战斗中的伤害，还是它是性选择？该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Pedipalpi is a lineage comprising three little known groups of arachnids: Amblypygi (whip spiders), Schizomida (short-tailed whip scorpions or micro-whip scorpions), and Thelyphonida (vinegaroons or whip scorpions). These nocturnal predators, which inhabit tropical and subtropical habitats on all major landmasses except Antarctica, are important for controlling insect populations and have hardly changed anatomically in 300 million years. What little is known about their life history and behavior reveals complex courtship rituals, male combat, territoriality, sociality, parental care, and chemical defense with an arsenal of noxious defense secretions. Despite the deep evolutionary timescale, global distribution, ecological importance, and fascinating life history and behavior of Pedipalpi, little progress on their classification has been made in a century, and their branch of the Tree of Life is barely assembled, hindering the testing of hypotheses concerning their evolution. By leveraging technological advances in genomics, microscopy, imaging, and informatics, and integrating anatomical and genomic data, this project will build the first comprehensive tree of life for living and fossil Pedipalpi, train a new generation of experts on these poorly studied arachnids, and disseminate results to the public. Two Ph.D. students and two postdoctoral associates, from groups under-represented in science, will be supported. Each year, an undergraduate, two high school students, and two citizen scientists will be involved in research. Courses on the biology and classification of Pedipalpi, with an introduction to the local fauna, will be presented on four continents. New material, data, and images will enhance scientific infrastructure. Results, data, and educational outreach materials will be disseminated at meetings, online, and via nationally distributed classroom magazines.The project has four primary aims. (1) Using a high-throughput, targeted enrichment approach, ca. 100,000 base-pairs of DNA sequence, per specimen, will be generated for representatives of all major lineages, 70% of the genera, and 30% of the species of living Pedipalpi. (2) A matrix of morphological observations will be compiled for all species in the genomic dataset and representatives of extinct lineages of Pedipalpi and their chelicerate relatives. The phylogeny and morphology will be used to (3) present a predictive classification of Pedipalpi above the level of genus and conduct monographic taxonomic revisions of four lineages, and (4) investigate questions concerning the evolution and diversification of Pedipalpi. How, when, and where did the major lineages of Pedipalpi diversify, and which key innovations enabled them to do so? Is morphological specialization to life in caves, commonly inhabited by Pedipalpi, an irreversible, evolutionary dead-end? Is sexual dimorphism in the spinose pedipalps (claws) of Amblypygi ancestral or derived, and did it evolve to reduce injury in ritualized male combat, or was it sexually selected?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.