Complexity in the oldest animal ecosystems

最古老的动物生态系统的复杂性

• 批准号: RGPIN-2019-05405
• 负责人: Laflamme, Marc
• 金额: $ 1.82万
• 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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=746969
• 关键词: Complexity; oldest; animal; ecosystems

The Ediacaran Period (635-541 Ma) captures a fundamental stage in the evolution of complex life. Typifying this time are the Ediacara biota, a globally distributed group of large, soft-bodied, morphologically complex multicellular organisms whose biological affinities are strongly contested. My research combines data-driven modeling and advanced instrumentation with experimental procedures and field work into a single research program targeting three fundamental questions: 1) to what extent is preservation biasing the fossil record of early life? 2) How did the Ediacara biota perform basic biological functions? And 3) how complex were the oldest animal ecosystems? Preservational biases must be considered when evaluating the fidelity of the fossil record. My research group applies multidisciplinary laboratory-based investigations into soft-tissue fossilization by designing decay chambers that continuously monitor and report the geological, biological, and chemical products of decay (pH, CO2, H2S, CH4, NO2, etc.), in addition to sediment/liquid/gas extraction tools that allow for sampling with minimal disruption. Through this approach, we are able to identify key stages in the tempo and mode of exceptional fossilization, and set realistic limits on the fidelity of the fossil record of early life. In order to address the biological functions of the Ediacara biota, I combine phylogenetic studies with functional morphology. My research group has pioneered the use of digital reconstructions of Ediacaran organisms subjected to virtual oceanic conditions to demonstrate alternative feeding strategies and even propose mobility in forms that lack fossilized appendages. My approaches target how individual species interacted within an ecosystem, leading to evaluations of the hidden complexity within Ediacaran ecosystems. As ecosystem complexity can be investigated in many ways, my laboratory has developed innovative fuzzy ecospace modelling approaches that target the evolution, expansion, and even loss of strategic positions occupied by organisms within an ecosystem (i.e. niche). Given their antiquity, Ediacaran ecosystems are typically interpreted as relatively simple. However, paleoecological studies stemming from my research have demonstrated 1) the likelihood of competitive interactions between many Ediacara biota leading to speciation, 2) expanded reproductive strategies among the oldest Ediacara biota, 3) expanded trophic structure in the latest Ediacaran with the advent of penetrative burrowing and predation, and 4) a greater diversity of mobile Ediacara biota than previously hypothesized. Targeted field programs in Namibia and Iran will provide the data necessary to evaluate how niche creation, occupation, and destruction has changed throughout the Ediacaran and into the Cambrian. Ultimately, my research will be central to evaluating the magnitude of biotic interactions and turnover at the dawn of animal life.

埃迪卡拉纪（635-541 Ma）是复杂生命进化的一个基本阶段。这一次的典型是埃迪卡拉生物群，这是一个全球分布的大型，软体，形态复杂的多细胞生物群，其生物亲和力受到强烈质疑。我的研究将数据驱动的建模和先进的仪器与实验程序和实地工作结合起来，成为一个单一的研究计划，针对三个基本问题：1）在多大程度上保护偏向早期生命的化石记录？2)埃迪卡拉生物群如何发挥基本的生物功能？（3）最古老的动物生态系统有多复杂？在评价化石记录的真实性时，必须考虑保存的偏差。我的研究小组通过设计衰变室，连续监测和报告衰变的地质，生物和化学产物（pH值，CO2，H2S，CH 4，NO2等），将多学科实验室研究应用于软组织分解，此外，还可以使用沉积物/液体/气体提取工具，在最小干扰的情况下进行采样。通过这种方法，我们能够确定异常化石化的克里思和模式的关键阶段，并对早期生命化石记录的保真度设定现实的限制。 为了解决埃迪卡拉生物群的生物功能，我联合收割机系统发育研究与功能形态学。我的研究小组率先使用数字重建的埃迪卡拉生物受到虚拟海洋条件下，以证明替代喂养策略，甚至提出移动的形式，缺乏仿生附肢。我的方法针对单个物种如何在生态系统中相互作用，从而评估埃迪卡拉生态系统中隐藏的复杂性。 由于生态系统的复杂性可以通过多种方式进行研究，我的实验室开发了创新的模糊生态空间建模方法，其目标是生物在生态系统（即生态位）中所占据的战略地位的演变，扩张甚至丧失。鉴于其古老性，埃迪卡拉生态系统通常被解释为相对简单。然而，从我的研究中产生的古生态学研究表明：1）许多埃迪卡拉生物群之间的竞争性相互作用导致物种形成的可能性，2）最古老的埃迪卡拉生物群中扩展的生殖策略，3）最新埃迪卡拉的营养结构随着穿透式穴居和捕食的出现而扩大，以及4）比以前假设的更大的移动的埃迪卡拉生物群的多样性。在纳米比亚和伊朗的有针对性的实地项目将提供必要的数据，以评估生态位的创造，占领和破坏如何在整个埃迪卡拉纪和寒武纪发生变化。最终，我的研究将是核心，以评估生物相互作用和营业额的大小在动物生命的黎明。