Perturbation of the Earth System at the Proterozoic-Phanerozoic transition and the resilience of the biosphere

查尔斯·达尔文最大的难题是，为什么以动物化石形式出现的复杂生命在大约5.2亿年前（Ma）的岩石中突然出现，这就是广为人知的寒武纪大爆发。近几十年来，在整个寒武纪时期（始于2000万年前），甚至可以说是在整个埃迪卡拉纪时期（直接跟随全球“雪球地球”冰川（~715 - 635 Ma）），都发现了保存完好的动物化石。这些异常矿床大多发现于华南地区，华南地区拥有当时保存最完好的海洋环境地质记录。在这个真正的中英合作项目中，我们建议利用中国南方的岩石档案来构建一个更高分辨率的四维（时空）图像，展示最早期动物及其环境的进化历史。为了实现这一目标，我们的团队结合了英国和中国研究团队在以下方面的互补专业知识：1）地质年代学-岩石测年; 2）地球化学-重建营养和耦合的地球化学循环（O和C）; 3）生物基因组学-制作基于遗传的生命树，以与化石记录进行比较，并填补空白;最后是数学模型，这将使我们能够捕捉地质信息，以测试有关动物进化对环境稳定性影响的关键假设。我们的项目旨在解决三个核心科学问题：1）在这些演化辐射过程中，C、O、N、P和S的耦合地球化学循环是如何变化的？2)是环境因素，如氧气水平，而不是生物驱动因素，如特定动物特征的出现，决定了进化变化的轨迹吗？3）动物的崛起是否增加了生物圈对扰动的恢复力？最后一个问题与今天的生物圈有关，因为现代地球系统及其稳定反馈就是在这一关键时期出现的。通过更详细地研究它，并建立关键事件之间的时间关系和因果关系，我们可以发现现代地球系统是如何构建的，包括哪些生物特征是其持续气候和生态系统稳定性的关键。该项目的另一个目标是加强英国和中国研究人员之间现有的和建立新的，真正有意义的合作。我们将通过四个研究团队的共同努力，将所有现有和新的数据整合到一个名为地球生物多样性数据库的国际数据库中，共享一个联合建模框架，并通过为参与该项目的早期职业研究人员提供合作培训，实现这一目标。

Charles Darwin's great dilemma was why complex life in the form of fossil animals appear so abruptly in rocks around 520 million years ago (Ma), in what is widely known as the Cambrian explosion. During recent decades, exceptionally preserved animal fossils have been found throughout the Cambrian Period, which began 20 million years earlier, and arguably even through the entire, preceding Ediacaran Period, which directly followed the worldwide 'Snowball Earth' glaciations (~715 - 635 Ma). Most of these exceptional deposits were discovered in South China, which possesses the best preserved and dated geological record of the marine environment for this time. In this genuinely collaborative UK-China project, we propose to use the South China rock archives to construct a much higher resolution, four-dimensional (temporal-spatial) picture of the evolutionary history of the earliest animals and their environment. Towards this endeavour, our group combines complementary expertise on both the UK and Chinese research teams in: 1) geochronology - the dating of rocks; 2) geochemistry - for reconstructing nutrient and the coupled biogeochemical cycle (O and C); 3) phylogenomics - for making a genetically-based tree of life to compare with, and fill gaps in the fossil records; and finally 4) mathematical modelling, which will enable us to capture geological information, in such a way as to test key hypotheses about the effects of animal evolution on environmental stability. Our project aims to address three central scientific questions: 1) How did the coupled biogeochemical cycles of C, O, N, P and S change during these evolutionary radiations?; 2) Did environmental factors, such as oxygen levels, rather than biological drivers, such as the emergence of specific animal traits, determine the trajectory of evolutionary change?; and 3) Did the rise of animals increase the biosphere's resilience against perturbations? This last question has relevance to today's biosphere, as the modern Earth system and its stabilising feedbacks arose during this key interval. By studying it in more detail, and establishing temporal relationships and causality between key events, we can find out how the modern Earth system is structured, including which biological traits are key to its continued climatic and ecosystem stability. One further goal of this project is to strengthen existing and establish new, and genuinely meaningful collaborations between the UK and Chinese investigators. We will achieve this by working jointly in four research teams, by integrating all existing and new data into an international database, called the Geobiodiversity Database, sharing a joint modelling framework, and by providing collaborative training for the early career researchers involved in this project each year of the project.