Phylogenetics and Evolutionary Biomechanics of Coral Reef Fishes

鱼的家庭Labridae是一个多样化的群体，近600种，栖息在热带和温带海洋沃茨在世界各地，并构成了一个主要部分的多样性发现的珊瑚礁。在我们的理解labrid家庭树和摄食行为的生物力学研究的进展将允许在珊瑚礁鱼类进化的探索。 该项目的第一个目标是收集新的DNA序列数据的几个物种组内的Labridae。在先前的NSF支持下，使用115个物种的数据生成了Labridae的家谱。基于来自细胞不同部分的四个基因（来自细胞核和细胞核的各2个），该树上的系统发育关系的分辨率非常好。然而，几个大的物种群仍然没有得到解决。在这个项目中，将获得120个额外分类群的基因序列，这些序列适合于物种水平的问题。此外，该项目还将研究两个与鱼类头骨早期生长和发育有关的基因。这些基因包括Otx1，一个在头部生长中起作用的基因和Dlx2，一个参与下颌形成和牙齿发育的基因。这些基因的序列将在50个物种中收集，这些物种具有不同的头骨结构和颌骨解剖结构。因此，这项研究将提供来自许多物种和许多基因的新信息，其中一些已知的调控参与构建动物的关键部分，头骨。该提案的第二个目标是将联合收割机进化树与工程设计的概念和进食行为的知识相结合，以研究头骨功能。进化收敛的具体假设将被测试，以确定相同的工程解决方案是否已在该集团的历史上多次实现。在这个家庭中发现的颌骨和头骨的极端修改使他们成为颅骨结构和功能进化的模型系统。生物力学工程模型允许计算基本的进食力学，如颌骨闭合力和速度，以及颌骨突出。作为物理构造和计算机模型生成的生物力学模型对于研究和教育是有用的。结合许多物种的进化与功能，该项目将研究地球上最多样化的脊椎动物之一的生物力学的进化变化。从基因到组织再到整个生物体，对生物结构和功能的综合理解是生物学的主要前沿之一。该项目有助于通过测试特定的假设功能进化使用分子生物学和工程概念的目标。 该项目以多种方式为教育、培训、展览和研究基础设施做出贡献。首席研究员在芝加哥大学教授本科课程，每年在菲尔德博物馆的藏品中举行实验室练习。学生在大学，研究生和博士后水平参与了拟议的研究的各个方面，包括测序，分析和生物力学。目前正在与来自奥地利、澳大利亚、智利、肯尼亚、马达加斯加、新西兰、菲律宾和泰国的人进行合作。博物馆的展品现在展出的功能模型的鱼头功能开发从国家科学基金会资助的研究，展品计划在菲尔德博物馆的系统发育和功能研究。PI给博物馆讲座，在公共广播电台发言，参观当地学校，并提出珊瑚礁鱼类生物学的团体，如老年旅馆和扶轮社在芝加哥地区。该提案中的动物功能的物理和计算机模型是课堂教育，研究培训和博物馆展览的绝佳工具。

Fishes of the family Labridae are a diverse group of nearly 600 species that inhabit tropical and temperate marine waters throughout the world and constitute a major segment of the diversity found on coral reefs. Advances in our understanding of the labrid family tree and study of the biomechanics of feeding behavior will allow exploration of evolution in coral reef fishes. The first goal of this project is to collect new DNA sequence data for several species groups within the Labridae. With previous NSF support, a family tree for the Labridae was generated using data for 115 species. Resolution of phylogenetic relationships on this tree was excellent based on four genes from different parts of the cell (2 each from the mitochondrion and the nucleus). However several large species groups remain unresolved. In this project, sequences of genes that are appropriate for species-level questions will be obtained for 120 additional taxa. In addition, this project will investigate two genes involved in early growth and development of fish skulls. These include Otx1, a gene that plays a role in head growth and Dlx2, a gene involved in both lower jaw formation and tooth development. Sequences for these genes will be collected in 50 species, having diverse skull structures and jaw anatomy. Thus, this study will provide new information from many species and many genes, some of which have known regulatory involvement in building a key part of the animal, the skull. The second objective of the proposal is to combine evolutionary trees with concepts from engineering design and knowledge of feeding behavior to study skull function. Specific hypotheses of evolutionary convergence will be tested to determine whether the same engineering solution has been achieved multiple times in the history of the group. The extreme modifications of jaws and skull found in this family make them a model system for evolution in cranial structure and function. Biomechanical engineering models allow calculation of basic feeding mechanics such as jaw closing force and speed, and jaw protrusion. Biomechanical models, generated as physical constructs and computer models, are useful for research and education. Combining evolution with function in many species, this project will examine evolutionary change in the biomechanics of one of the most diverse radiations of vertebrates on Earth. The movement toward an integrated understanding of biological structure and function, from genes to tissues to whole organisms, is one of the major frontiers of biology. This project contributes to that goal by testing specific hypotheses of functional evolution using molecular phylogenies and engineering concepts. This project contributes to education, training, exhibits, and research infrastructure in many ways. The Principal Investigator teaches undergraduate courses at the University of Chicago and lab exercises are held each year in the collections of the Field Museum. Students at the college, graduate, and postdoctoral levels are involved with all aspects of the proposed research, including sequencing, analysis, and biomechanics. Collaborations are underway with people from Austria, Australia, Chile, Kenya, Madagascar, New Zealand, The Philippines, and Thailand. Museum exhibits are now on display that feature models of fish head function developed from NSF-funded research, and exhibits are planned to feature both phylogenetic and functional research at the Field Museum. The PI gives museum lectures, has spoken on public radio, visits local schools, and presents coral reef fish biology to groups such as Elder Hostel and Rotary in the Chicago area. Physical and computer models of animal function featured in this proposal are fantastic tools for classroom education, research training, and museum exhibits.