Patterns of diversification in terrestrial vertebrate evolution

陆生脊椎动物进化的多样化模式

• 批准号: RGPIN-2015-06212
• 负责人: Reisz, Robert
• 金额: $ 6.56万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614009
• 关键词: Patterns; diversification; terrestrial; vertebrate; evolution

The fossil record of vertebrates, with preservation of complex skeletons and teeth provides the best evidence of evolutionary dynamics across large temporal scales for investigating the mechanisms and conditions that led to the modern ecosystems. The origin and initial stages of amniote evolution represent the start of a great chapter in earth's history, the conquest of land by vertebrates. Within 6 million years of their first appearance 311 Million year ago (Ma), we see rapid evolutionary radiations that extend to the present, and include extant squamates, turtles, crocodiles, birds, mammals, and many extinct relatives, including dinosaurs. Ongoing research in vertebrate paleontology including the anatomy, taxic diversity, and phylogenetic relationships of early amniotes will continue to be part of the present proposal because new discoveries can have major impacts on our understanding of vertebrate evolution. Here I propose to combine these ongoing investigations with studies of ecological diversity. I therefore plan to evaluate evolutionary changes in both taxic and ecological diversity through time as reflected by their reconstructed feeding behaviour. First, I will integrate for the first time calibrated phylogenetic analyses across clades for a better understanding of patterns of diversification and evolution within communities. I will then examine morphological variation (disparity), including dental and mandibular diversity in comparative, phylogenetic and temporal contexts in order to track the ecological diversification of early amniotes as they evolved to access formerly unoccupied ecospaces and novel food resources. Morphometric analyses of variation in tooth and jaw shape, and size in successive Paleozoic communities will be organized into 8 time bins that extend from the Late Carboniferous (311 Ma) to the Middle Permian (272 Ma). In order to understand the ecological diversity present in these Paleozoic communities I plan to quantify variation in tooth and jaw morphology, and deduce the dietary preferences in each taxon. Several other variables, including cranial and postcranial data may be included in the total disparity analyses. Since extant reptiles show morphological similarities to Paleozoic terrestrial amniotes, squamates can be used as extant model systems. My research group will develop for the first time ecomorphological models that can be applied to early amniotes, and test the hypothetical importance of dietary shifts in the ecological diversification of amniotes. The novel use of combined ecological and taxic diversity patterns represents one of the transformative ways in which we approach this paleobiological research program. These analyses will shed new light on the community structure and evolution of early amniotes during the initial stages of terrestrial vertebrate evolution.

脊椎动物的化石记录， 骨骼和牙齿提供了最好的证据， 大的时间尺度来研究导致 现代生态系统。的起源和初始阶段 新的进化代表了一个伟大的 脊椎动物征服陆地的历史。仅6 它们首次出现的百万年前 3.11亿年前（Ma），我们看到快速进化的辐射，延伸到 包括现存的有鳞动物，海龟，鳄鱼， 鸟类、哺乳动物和许多已灭绝的近亲，包括恐龙。 正在进行的古脊椎动物研究包括解剖学， 分类多样性，以及早期的系统发育关系将继续存在 因为新的发现可能会有重大的影响， 影响了我们对脊椎动物进化的理解在这里我提议将联合收割机 这些正在进行的调查与生态多样性的研究。因此我 计划评估分类和生态多样性的进化变化 通过它们重建的进食行为来反映。首先我 将首次整合校准的系统发育分析， 更好地理解多样化和进化模式的分支 在社区内。然后，我将检查形态变化（差异）， 包括牙齿和下颌骨的比较，系统发育和 时间背景，以跟踪生态多样性的早期 它们进化到可以进入以前无人居住的生态空间和新的食物 资源牙齿和颌骨形状及大小变异的形态测量学分析 在连续的古生代群落中，将被组织成8个时间仓， 从晚石炭世（311 Ma）延伸至中二叠世（272 Ma）。在 为了了解这些古生代的生态多样性， 我计划量化牙齿和颌骨形态的变化， 推断出每个分类群的饮食偏好。其他几个变量， 包括颅和颅后数据 分析。由于现存的爬行动物与古生代的动物在形态上相似， 陆栖类、有鳞类可作为现存模式系统。我 研究小组将首次开发生态形态模型， 应用于早期的蚊子，并测试饮食的假设重要性， 生态多样性的变化。结合生态的新用途 分类多样性模式代表了一种变革方式， 我们着手进行这个古生物学研究项目。这些分析将为研究古生物群落的结构和演化提供新的线索。 陆地脊椎动物进化的初始阶段。