NSF Postdoctoral Fellowship in Biology FY 2017: Evolutionary morphology and cranial constraints in piranhas, pacus, and their allies

该行动资助2017财年美国国家科学基金会生物学博士后研究奖学金，扩大生物学中代表性不足群体的参与。该奖学金支持以创新方式利用生物馆藏的研究和培训。食人鱼和它们的盟友有近100种，尽管它们的下颌看似简单，但它们捕食的猎物从整条鱼到坚果、水果和树叶等植物都有。研究人员可以通过研究捕食者及其猎物的历史，并注意到哪些行为、结构和材料在串联进化（进化趋同），来理解生物材料和结构是如何以及为什么发生变化的。了解解剖学是如何进化的第一步是建立一个现存食人鱼、帕库鱼和它们的亲戚的进化谱系（系统发育），以此作为一个框架。然后，该项目将研究食人鱼及其盟友的进食解剖结构是如何构建的，这些结构在捕食不同猎物时是如何表现的，并在这些鱼类的进化史上绘制这些特征。该研究员将使用靶向外显子捕获方法构建serrasalmid鱼类的尖端系统基因组树。这些进化关系将被用作理解喂养性状进化的框架，通过碘增强对比染色和微计算机断层扫描（micro-CT）进行可视化。该研究员将使用生物力学建模方法，如FEA（有限元分析）来研究不同颅骨形状在进食过程中如何抵抗应力，并通过分析肌肉形态和微ct成像测量的颌骨杠杆动力学来量化进食性能。这个项目提出，食人鱼的头骨将显示出在颅骨结构强度、牙齿形状和进食性能之间的进化权衡。这些特征的某些组合也与特定的饮食有关，比如吃鳞片、吃水果和吃鱼等等。这个项目利用博物馆的分子收藏品来进一步了解像食人鱼这样有魅力的鱼类的进化关系。博物馆标本的形态成像将生成一个食人鱼CT模型数据库，用于教学和推广方法，任何人都可以免费下载和3D打印。培训目标包括获得一些最先进的解剖学可视化技术的经验，并对这些结构的材料和建筑行为进行建模。更广泛的影响包括针对有语言障碍的大学和大学预科学生的教育推广，吸引这些学生对科学的兴趣，增强他们进入学术界和其他研究型职业的信心和能力。这些研究的结果也将发表在同行评审的期刊上，并在科学会议上分享。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2017, Broadening Participation of Groups Under-represented in Biology. The fellowship supports research and training of the fellow utilizing biological collections in innovative ways. Piranhas and their allies number almost 100 species and despite deceptively simple jaws, these fishes consume prey ranging from whole fishes to plant matter like nuts, fruits, and leaves. Researchers can understand how and why biomaterials and structures have changed by studying the history of predators and their prey, and noting which behaviors, structures, and materials keep evolving in tandem (evolutionary convergence). The first step in understanding how anatomy has evolved is building an evolutionary genealogy (phylogeny) of living piranhas, pacu, and their relatives to use as a framework. This project will then examine how the feeding anatomy of piranhas and their allies is constructed, how these structures perform when feeding on different prey, and map these traits across the evolutionary history of these fishes.The fellow will construct a cutting-edge phylogenomic tree for serrasalmid fishes using targeted exon capture methods. These evolutionary relationships will be used as a framework for understanding feeding trait evolution, visualized through iodine-enhanced contrast staining coupled with micro-computed tomography (micro-CT). The fellow will use biomechanical modeling methods like FEA (finite-element analysis) to examine how different skull shapes resist stresses during feeding, and quantify feeding performance by analyzing muscle morphology and jaw lever dynamics measured from micro-CT imaging. This project proposes that the skulls of piranhas will show evolutionary trade-offs among cranial architectural strength, tooth shape, and feeding performance. Certain combinations of these traits will also be correlated with specific diets like scale-eating, fruit-eating, and piscivory, among others. This project utilizes molecular collections from museums to further our understanding of the evolutionary relationships of charismatic fishes like piranhas. Morphological imaging of museum specimens will generate a database of piranha CT models for teaching and outreach methods, free for anyone to download and 3D print. Training goals include the fellow gaining experience in some of the most advanced techniques for visualizing anatomy and modeling the material and architectural behavior of these structures. Broader impacts include educational outreach targeting university and pre-university students with speech disabilities, engaging these student's interests in science, and reinforcing their confidence and ability for entering academia and other research-based professions. Results from the studies will also be published in peer-reviewed journals and shared at scientific meetings.