Living Fossils: Integrating Phylogenomics and Comparative Morphology to Assemble the Scorpion Tree of Life

在除南极洲以外的所有主要大陆的大多数陆地栖息地中，蝎子是占主导地位的节肢动物捕食者，在过去的4.35亿年中，它们的解剖结构几乎没有变化。全世界每年有120万只蝎子蜇伤导致3,250人死亡。蝎子毒液是一种神经毒素鸡尾酒，可以阻断神经冲动，为医学提供了巨大的潜力，包括治疗脑癌和自身免疫性疾病，非成瘾性止痛药和环保杀虫剂。尽管这些“活化石”的古老性、声名狼借性、全球分布性、生态学和医学重要性，但蝎子的分类是有争议的，蝎子生命树的解决也是模棱两可的，这阻碍了对有关蝎子进化的重要假设的测试，以及对蝎子毒液药理学潜力的探索。通过整合活蝎子和化石蝎子的基因组和形态学数据，该项目将提供迄今为止对蝎子生命树和蝎子进化位置的最全面分析。该项目将支持一个博士学位。学生和三名博士后助理，都来自代表性不足的群体。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。关于蝎子生物学、分类和医学重要性的课程，以及对当地动物群的介绍，将在四大洲举办。新的材料、数据和图像将增强科学基础设施。结果、数据和教育宣传材料将在网上和通过在全国发行的课堂杂志传播。首先，使用高通量、有针对性的富集方法，每个标本将产生大约300，000个碱基的DNA序列，用于所有主要谱系的代表，至少80%的活蝎子属，以及所有活的螯肢目。将完成基因组数据集中所有物种的形态观察矩阵，以及蝎子及其螯肢亲属灭绝谱系的代表。此外，蝎子发生学和形态学将用于提出属以上水平的蝎子的预测分类，并调查有关蝎子及其毒液的进化和多样化的问题。该项目将包括广泛的实地考察和与国际同事的合作，并将代表任何螯合物组的最全面的进化研究。更深入地了解毒液是如何在蝎子生命树中进化的，将为调整毒液在医学中的使用提供必要的数据。

Scorpions are dominant arthropod predators in most terrestrial habitats on all major landmasses except Antarctica, and their anatomy has changed very little in the past 435 million years. Every year, 1.2 million scorpion stings cause 3,250 human fatalities worldwide. Scorpion venoms, cocktails of neurotoxins that block nerve impulses, offer great potential for medicine, including treatment of brain cancer and autoimmune diseases, non-addictive painkillers, and ecofriendly insecticides. Despite the antiquity, notoriety, global distribution, ecological, and medical importance of these "living fossils", scorpion classification is contentious and the scorpion tree of life ambiguously resolved, hindering the testing of important hypotheses concerning scorpion evolution, and exploration of the pharmacological potential of scorpion venom. By integrating genomic and morphological data from living and fossil scorpions, this project will provide the most comprehensive analysis of the scorpion tree of life and the evolutionary position of scorpions, to date. The project will support a Ph.D. student and three postdoctoral associates, all from underrepresented groups. Each year, an undergraduate, two high school students, and two citizen scientists will be involved in research. Courses on scorpion biology, classification, and medical importance, 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 online and via nationally distributed classroom magazines.The project has several primary aims. First, using a high-throughput, targeted enrichment approach, approximately 300,000 bases of DNA sequence, per specimen, will be generated for representatives of all major lineages, at least 80% of the genera of living scorpions, and all living orders of Chelicerata. A matrix of morphological observations will be completed for all species in the genomic dataset and representatives of extinct lineages of scorpions and their chelicerate relatives. Additionally, the phylogeny and morphology will be used to present a predictive classification of scorpions above the level of genus and investigate questions concerning the evolution and diversification of scorpions and their venoms. The project will include extensive fieldwork and collaboration with international colleagues and will represent the most comprehensive evolutionary study of any chelicerate group. A greater understanding of how venom has evolved across the scorpion tree of life will provide the necessary data to fine-tune the use of venom in medicine.