Collaborative Research: Convergent evolution and diversification of the crab body plan over 200 million years

这个项目解决了生命研究中的一个基本问题：我们能否根据动物的形态来预测它们的进化成功？螃蟹是最具代表性的无脊椎动物之一，在水族贸易、渔业和水产养殖中发挥着不可或缺的作用，在世界各地的文化中都通过节日和游行来庆祝螃蟹。这项研究旨在为所有已知的活螃蟹和化石螃蟹家族建立生命之树，以调查这些动物在2亿多年的历史中是如何变化的。螃蟹的典型身体形态已经从类似龙虾的祖先中分别进化了好几次，而且在不同的螃蟹群体中也已经消失了好几次。新的螃蟹生命树将揭示螃蟹形状的独立得失是否预示着该群体的巨大生物多样性和生态多样性。螃蟹形式和功能的多样性将吸引高中生参与博物馆活动，本科生参与初级研究和鼓励批判性思维的课堂模块。实地考察将在巴拿马进行，在那里，一个热带螃蟹分类学培训课程将使美国和拉丁美洲的科学家沉浸在用于扩展和调查螃蟹生命树的技术中。在十足甲壳类动物中，获得螃蟹样的身体已经进化了4到5次，并且被认为是下目Brachyura（7000种真蟹）和Anomura（2500种包括瓷蟹、寄居蟹和帝王蟹）中巨大的多样化和生态成功的一个因素。本项目的目标是：(1)利用基因组（现存）和形态学（现存和化石）数据构建假蟹和真蟹的主干系统发育。(2)利用化石作为年龄标定，构建进化时间线；这将为推断蟹体平面演化的模式和地质时代提供依据。(3)检验在类蟹世系中，其多样化率是否相对于其姊妹群体有所增加，而当类蟹身体第二次消失时，其多样化率是否也有所下降。研究人员假设，至少有一些特征包含了可能的关键创新。这些目标将通过使用目标富集方法对500种螃蟹进行测序，对现存和化石分类群（包括所有螃蟹科的代表）进行形态学编码和成像，并部署尖端的分化时间分析和系统发育比较方法。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。

This project addresses a fundamental question in the study of life: can we predict the evolutionary success of animals based on their forms? Crabs are one of the most iconic groups of invertebrates, playing an integral role in aquarium trade, fisheries, and aquaculture, and are celebrated in cultures around the world through festivals and parades. This research aims to build the tree of life for all known living and fossil crab families, to investigate how these animals have changed over 200 million years of history. The typical body form that characterizes crabs has evolved separately several times from lobster-like ancestors, and also has been lost several times in different groups of crabs. The new crab tree of life will reveal whether the independent gains and losses of the crab shape predict the immense biodiversity and ecological versatility of the group. The inspiring diversity of crab form and function will engage high school students through museum activities, and undergraduate students in primary research and classroom modules incentivizing critical thinking. Fieldwork will be conducted in Panama, where a training course in tropical crab taxonomy will immerse US and Latin American scientists in the techniques used to expand and investigate the crab tree of life.The acquisition of a crab-like body form has evolved four to five times among decapod crustaceans, and has been proposed as a contributing factor to the immense diversification and ecological success within the infraorders Brachyura (7000 species of true crabs), and Anomura (2500 species including porcelain crabs, hermit crabs, and king crabs). The objectives of this project are: (1) To construct a well-supported backbone phylogeny for false and true crabs using genomic (extant) and morphological (extant and fossil) data. (2) To employ fossils as age calibrations to construct an evolutionary timeline; this will serve as the foundation for inferring the pattern and geological timing of crab body plan evolution. (3) To test if the rate of diversification has increased in crab-like lineages relative to their sister groups, and likewise has decreased when the crab-like body was secondarily lost. The researchers hypothesize that at least some traits comprise a possible key innovation. These objectives will be achieved by sequencing 500 crab species using target enrichment methods, morphological coding and imaging of living and fossil taxa (including representatives of all crab families), and the deployment of cutting-edge strategies for divergence time analysis and phylogenetic comparative methods.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.