DISSERTATION RESEARCH: Independent evolution and ancestral conditions in the gnathostome axial column

论文研究：颚口轴柱的独立进化和祖先条件

• 批准号: 1501749
• 负责人: Michael Coates
• 金额: $ 2.03万
• 依托单位: University of Chicago
• 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 2016-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501749&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Independent; evolution; ancestral

The presence of a backbone, even if only made of cartilage, is the feature that distinguishes vertebrate animals from their invertebrate relatives. Despite its central position in the body plans of all jawed vertebrates, the early evolutionary history and developmental mechanisms that gave rise to the vertebral column are not well understood. Across different vertebrate groups, and among fishes in particular, the vertebrae that make up the backbone are remarkably varied in their shape, composition, and structure. Furthermore, the early fossil record of the major groups of fishes shows that many evolved fundamental components of the vertebral column quite independently of others. The goals of this project are to document vertebral development in poorly studied groups such as sharks and skates, to determine how much independent evolution actually occurred in the deep history of vertebrae, and to provide essential comparisons with the current understanding of vertebral development in bony fishes.This project combines ancestral state reconstructions on gnathostome supertrees with computed tomography, gene expression, and fate mapping experiments to investigate the macroevolutionary patterns of vertebral evolution and development in fishes. Chondrichthyans are the main focus of the proposed research because they occupy a key phylogenetic position as the most proximate outgroup to the Osteichthyes. Chondrichthyans are often considered exemplars of ancestral vertebrate conditions in developmental and functional studies, but the primitive or derived status of much of their morphology is unclear and the subject of renewed research interest. Identifying ancestral conditions and homoplasy in the axial column complex is essential for the informed evaluation of studies and data obtained from alternative vertebrate model systems. Moreover, sharks as well as fossils are charismatic study subjects that effectively capture public interest. To help communicate the nature of this and other related projects to the public, the investigators will use computed tomographic scans (static and animated), and fossil shark specimens to educate students at local schools about the importance and relevance of evolutionary biology.

骨干的存在，即使仅由软骨制成，也是将脊椎动物与其无脊椎动物亲属区分开的特征。尽管在所有令人jaw的脊椎动物的身体计划中具有中心地位，但还没有很好地了解引起椎骨的早期进化史和发育机制。在不同的脊椎动物组中，尤其是在鱼类中，构成主链的椎骨在其形状，组成和结构上都有很大变化。此外，主要鱼类的早期化石记录表明，许多椎骨的基本成分完全独立于他人。该项目的目标是记录鲨鱼和溜冰鞋等研究较低的群体中的椎骨发展，以确定椎骨深层历史上实际发生了多少独立进化，并提供了与当前对骨鱼类椎骨发展的理解的必要比较。该项目结合了Gnathostome Supertrees上的祖传状态重建与计算机断层扫描，基因表达和命运映射实验，以研究鱼类椎体进化和发育的宏观进化模式。 Chondrichthyans是拟议研究的主要重点，因为它们占据了关键的系统发育位置，这是骨thy骨的最近外的群体。在发育和功能研究中，通常认为Chondrichthyans被认为是祖先脊椎动物条件的典范，但是其大部分形态的原始或衍生状态尚不清楚，并且是重新研究的主题。在轴向柱复合体中识别祖先条件和同质性，对于从替代脊椎动物模型系统获得的研究和数据的知情评估至关重要。此外，鲨鱼和化石是有效地吸引公共利益的魅力研究主题。为了帮助将该项目和其他相关项目的性质传达给公众，调查人员将使用计算机断层扫描（静态和动画），以及化石鲨鱼标本，以教育当地学校的学生有关进化生物学的重要性和相关性。