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.