Collaborative Research: Phenotypic and lineage diversification after key innovation(s): multiple evolutionary pathways to air-breathing in labyrinth fishes and their allies

对于某些生物群体来说，在进化尺度上，一些解剖结构或行为可以改变游戏规则。这些特征被称为“关键创新”，从根本上改变了生物体与环境的相互作用，并可能赋予其竞争优势。例如，创新可以避免与其他物种的竞争或捕食，或者允许进入新的栖息地和资源。对某些鱼类来说，一个潜在的关键创新是，它们有一种独特的呼吸器官，能够呼吸大气中的空气。这些呼吸空气的器官在斗鱼、gouramis和蛇头鱼等鱼类身上进化了好几次，这可能是它们数百万年前在世界各地成功传播的关键，也是它们在最近的生物入侵（如蛇头鱼）中成功传播的关键。该项目将研究空气呼吸结构是否是关键的创新，然后回答这些结构如何改变内在（解剖）或外在（生态）进化动力学。该项目将使用高分辨率微计算机断层成像（microCT），结合对比染色和组织学来深入了解整个Anabantaria （gouramis，蛇头，刺鳗和沼泽鳗）的空气呼吸器官的多样性。使用系统发育比较框架，研究小组将评估跨猿不同的空气呼吸结构的同源性。三维几何形态测量学将用于捕捉这些鱼类的头骨形状多样性，无论是呼吸空气的还是不呼吸空气的物种。最后，研究小组将测试呼吸空气的结构是否是关键的创新，然后回答这些结构如何改变进化动力学，要么通过(1)为大陆入侵提供新的机会，(2)促进体型多样化，或者(3)通过改变容纳呼吸空气器官的头骨如何适应不断变化的角色的基本原理。为了使这项研究产生更广泛的影响，路易斯维尔大学的研究小组将与密歇根大学自然历史博物馆的同事合作进行推广和培训。路易斯维尔大学的研究团队，PI，博士后和学生，将与路易斯维尔动物园社区项目办公室合作，在现有项目的基础上，增加孩子们对动物和彼此的同情心。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。

Some anatomical structures or behaviors can be game-changing at evolutionary scales for certain groups of organisms. Such traits, called “key innovations”, radically alter how an organism interacts with its environment, and may confer competitive advantages. Examples are innovations that enable avoiding competition or predation with other species, or allowing access to new habitats and resources. A potential key innovation for some fishes is the ability to breathe atmospheric air with a unique air-breathing organ. These air-breathing organs have evolved several times in fishes such as bettas, gouramis, and snakeheads, and may have been the key to their success in spreading across the world millions of years ago and again during more recent biological invasions (e.g., snakeheads). This project will examine whether air-breathing structures are key innovations and then answer how these structures alter intrinsic (anatomical) or extrinsic (ecological) evolutionary dynamics.This project will use high resolution micro-computed tomographic imaging (microCT), coupled with contrast-staining and histology to provide insight into the diversity of air-breathing organs across the Anabantaria (gouramis, snakeheads, spiny and swamp eels). Using a phylogenetic comparative framework, the research team will assess the homology of different air-breathing structures across anabantarians. Three-D geometric morphometrics will be used to capture skull shape diversity in these fishes, air-breathing and non-air-breathing species alike. Finally, the research team will test whether air-breathing structures are key innovations and then answer how these structures alter evolutionary dynamics, either by (1) providing new opportunities for continental invasions, (2) facilitating body shape diversification, or (3) by changing the fundamentals of how the skull, which houses the air-breathing organ, adapts to changing roles. For the Broader Impacts of this study, the research team at University of Louisville will partner with colleagues at the University of Michigan Museum of Natural History for outreach and training. The University of Louisville research team, PI, post docs and students, will partner with the Louisville Zoo community programs office to build on existing programs aimed at increasing children’s empathy towards animals and each other.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.