DISSERTATION RESEARCH: Innovation and constraint: the evolution of power-amplified feeding in syngnathiform fishes

论文研究：创新与约束：合颌鱼类功率放大摄食的演化

• 批准号: 1500800
• 负责人: Peter Wainwright
• 金额: $ 2.03万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1500800&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Innovation; constraint; evolution

Syngnathiformes (seahorses, pipefishes, trumpetfish and relatives) are a group of fishes with unusual and novel modes of locomotion, reproduction, and feeding. Nearly all species are characterized by an elongated snout, which they rotate towards prey during feeding strikes. Recent research has shown that seahorses and pipefish are using power amplification to achieve extremely fast rotations, resulting in strikes that are among the fastest recorded for any fish (less than 2.5 milliseconds). This research will reconstruct the sequential evolutionary assembly of this mechanically extreme feeding mechanism and will investigate the consequences of this feeding mechanism on head shape diversity. The findings of this work will advance knowledge about how complex structure-function relationships evolve and influence subsequent structural evolution. The study will produce set of phylogenetic trees that reveal the evolutionary relationships among over 200 syngnathiform species. These will be a valuable resource and shared with other researchers to advance knowledge of the evolutionary history of this unique and unusual group of fishes. Other data and products from this research, including slow-motion videos, will engage a wide audience in the diversity of fish feeding strategies by incorporation into existing coursework at the University of California, Davis and through YouTube. In addition to forming an ambitious and integrative doctoral dissertation, this research will involve undergraduates interested in pursuing STEM related fields through hands-on training and experience. This research will investigate the evolution of a mechanically extreme and complex feeding mechanism in syngnathiform fishes, beginning with the inference of a phylogeny using modern hybrid-enrichment (ultraconserved elements, UCEs) and next-generation sequencing technologies (Objective #1). Previous research has shown that seahorses and pipefish use power amplification to rotate their head towards prey faster than would be possible by direct muscle activation, and it has been proposed that this mechanism relies on a unique pivot joint in the skull. A combination of morphological and functional approaches including high-speed video, biomechanical modeling, and micro-CT scanning will be used to characterize and compare the feeding functional morphology of lineages related to seahorses and pipefish (Objective #2). The phylogeny from Objective #1 will be used to reconstruct the evolutionary history of the structural and functional changes necessary for power-amplified feeding in syngnathiform fishes and to test hypotheses about how the possession of this specialized mechanism has influenced the evolution of head shape in syngnathiforms (Objective #3). Models of continuous character evolution will to be fit to craniofacial shape data and compared in the software program OUwie to test the hypothesis that the possession of power amplification exerts strong stabilizing selection on craniofacial morphology. While the literature focuses on innovations that increase diversity, this work incorporates a model-testing approach to determine whether this novel feeding mechanism may constrain morphological diversification at macroevolutionary timescales.

Syngnathiformes（海马，烟斗，小号鱼类和亲戚）是一群具有不寻常和新颖的运动，繁殖和喂养方式的鱼类。几乎所有物种的特征都是细长的鼻子，它们在进食期间向猎物旋转。最近的研究表明，海马和Pipefish正在使用功率放大来实现极快的旋转，从而导致罢工是任何鱼类记录最快的爆发（小于2.5毫秒）。这项研究将重建这种机械极端喂养机制的顺序进化组装，并将研究这种饲料机制对头部形状多样性的后果。这项工作的发现将促进有关复杂结构 - 功能关系关系如何演变和影响随后的结构演变的知识。该研究将产生一组系统发育树，这些树木揭示了200多种Syngnathiorper物种之间的进化关系。这些将是一种宝贵的资源，并与其他研究人员共享，以促进对这种独特和不寻常的鱼类的进化历史的了解。这项研究中的其他数据和产品，包括慢动作视频，将通过在加利福尼亚大学，戴维斯大学和YouTube的现有课程中纳入鱼类喂养策略的多样性。除了形成雄心勃勃的综合博士论文外，这项研究还将涉及有兴趣通过动手培训和经验追求STEM相关领域的大学生。这项研究将研究Syngnathiorm Fishes中机械极端和复杂的喂养机制的演变，首先是使用现代杂种富集（超级保守的元素，UCES）和下一代测序技术（目标＃1）推断系统发育。先前的研究表明，海马和烟斗利用功率放大来使其头部朝着猎物旋转比直接肌肉激活更快的速度，并且已经提出这种机制依赖于头骨中的独特枢轴关节。形态学和功能方法的结合包括高速视频，生物力学建模和微CT扫描将用于表征和比较与海马和烟斗相关的谱系的饲喂功能形态（目标＃2）。目标＃1的系统发育将用于重建Syngnathiorper Fishes中功率放大喂养所必需的结构和功能变化的进化历史，并测试有关该专业机制的拥有的假设如何影响Syngnathathersiform中头部形状的演化（目标＃3）。连续特征演化的模型将适合颅面形状数据，并在软件程序中进行比较，以检验以下假设：功率放大的拥有可以对颅面形态产生强大的稳定选择。尽管文献着重于增加多样性的创新，但这项工作结合了一种模型测试方法，以确定这种新颖的喂养机制是否可以限制宏观进化时间标准的形态多样性。