Radiation and diversification patterns in early jawed vertebrates

早期有颌脊椎动物的辐射和多样化模式

• 批准号: RGPIN-2019-06133
• 负责人: Cloutier, Richard
• 金额: $ 2.4万
• 依托单位: Université du Québec à Rimouski
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738731
• 关键词: Radiation; diversification; patterns; early; jawed

Jawed vertebrates, or gnathostomes, account for 99.8% of living vertebrate species. Living gnathostomes include some 1 270 species of cartilaginous fishes (sharks, skates, rays and chimaeras), 29 000 species of ray-finned fishes (actinopterygians) and 33 880 species of tetrapods including our own species. This exceptional diversity is the result of a 440-million-year-long history that has been accompanied by events of evolutionary radiations. Early gnathostome key innovations include the presence of jaws and teeth, paired olfactory organs, pelvic fins and girdles and intromittent reproductive organs. These anatomical novelties have provided ecological, behavioral and reproductive advantages that were presumably associated with their early adaptive radiation. Because of these novelties, Devonian (419-359 Ma) gnathostomes were cosmopolitan in distribution, lived almost exclusively in aquatic habitats, occupied the whole food web and ranged in size from 2 cm to 4 m. Over the past decade, the discovery of new fossils of jawed vertebrates, the use of new cutting-edge technologies (micro- and nano-CT scan, synchrotron X-ray microtomography) and new analytical methods have shed light on gnathostome phylogeny. The evolutionary success of gnathostomes has been attributed alternately to the origin of the key innovations, ecological or environmental shifts, or their paleogeographic distribution. However, none of these scenarios have been framed in a broad-scale phylogeny in order to test hypotheses about biotic and abiotic factors which might have triggered the radiation. Notwithstanding the paramount importance of radiations during the evolution of life, an integrative framework for evolutionary radiation hypotheses is still lacking. For the next 5 years, the main goal of my research program will be to document the evolutionary radiation of jawed vertebrates by identifying rapid temporal changes in terms of the number of species, rates of evolution as well as rapid divergences in morphology and ecology. All these components will be integrated into a novel phylogenetic framework in order to identify factors acting as drivers of radiations. This quest for the "when, where and how" gnathostomes originated will led to an integrative and innovative approach to studying the origin and early radiation of taxonomic groups. Using the jawed vertebrate radiation, I wish to contribute to the general theory of evolutionary radiations as well as training highly qualified personnel in evolutionary biology. Increasingly interpretation of the past-both recent past and deep time-helps to understand the processes that generate and maintain diversity in time and space. A better understanding of evolutionary radiations and triggering factors is essential to comprehend not only past evolution but also the ongoing effects of global changes on biodiversity.

有颌脊椎动物占现存脊椎动物物种的99.8%。现存的颌口动物包括约1270种软骨鱼(鲨鱼、溜冰鱼、银鱼和嵌合体)，29000种鳍鱼(放线鳍目)和33880种四足动物，包括我们自己的物种。这种特殊的多样性是4.4亿年历史的结果，伴随着进化辐射的事件。早期的关键创新包括颌骨和牙齿、成对的嗅觉器官、腹鳍和腰带以及插入的生殖器官。这些解剖学上的新奇事物提供了生态、行为和生殖方面的优势，这些优势可能与它们早期的适应性辐射有关。由于这些新鲜事，泥盆纪(419-359 Ma)的颌口动物分布广泛，几乎完全生活在水生栖息地，占据了整个食物网，大小从2厘米到4米不等。在过去的十年里，新的有颌脊椎动物化石的发现，新尖端技术(微纳CT扫描，同步辐射X射线显微成像)的使用和新的分析方法的使用，揭示了颌口动物的系统发育。节肢动物的进化成功与关键创新的起源、生态或环境变迁或它们的古地理分布交替地被归因于。然而，这些情景中没有一个是为了测试可能引发辐射的生物和非生物因素的假设而在大范围的系统发展史中框定的。尽管辐射在生命进化过程中具有至高无上的重要性，但进化辐射假说的综合框架仍然缺乏。在接下来的5年里，我的研究计划的主要目标将是通过识别物种数量、进化速度以及形态和生态上的快速分化来记录有颌骨脊椎动物的进化辐射。所有这些组成部分将被整合到一个新的系统发育框架中，以确定作为辐射驱动因素的因素。这种对“何时、何地和如何”起源的探索将导致一种综合和创新的方法来研究分类学群体的起源和早期辐射。利用脊椎动物的下巴辐射，我希望为进化辐射的一般理论做出贡献，并培训进化生物学方面的高素质人员。越来越多地解释过去--无论是最近的过去还是深刻的时间--有助于理解产生和保持时间和空间多样性的过程。更好地了解进化辐射和触发因素不仅对于理解过去的进化，而且对于理解全球变化对生物多样性的持续影响，都是至关重要的。