The Proterozoic record of eukaryotes

Proterozoic strata host evidence of global “Snowball Earth” glaciations, large perturbations to the carbon cycle, proposed changes in the redox state of oceans, the diversification of microscopic eukaryotes, and the rise of metazoans. Over the past half century, the number of fossils described from Proterozoic rocks has increased exponentially. These discoveries have occurred alongside an increased understanding of the Proterozoic Earth system and the geological context of fossil occurrences, including improved age constraints. However, the evaluation of relationships between Proterozoic environmental change and fossil diversity has been hampered by several factors, particularly lithological and taphonomic biases. Here we compile and analyze the current record of eukaryotic fossils in Proterozoic strata to assess the effect of biases and better constrain diversity through time. Our results show that mean within assemblage diversity increases through the Proterozoic Eon due to an increas...元古宙（Proterozoic）地层保存有全球性“雪球地球（Snowball Earth）”冰期事件、碳循环（carbon cycle）剧烈扰动、学界提出的海洋氧化还原状态变化、微观真核生物（eukaryotes）的多样化演化以及多细胞动物（metazoans）起源的相关证据。过去半个世纪间，元古宙岩石中被正式描述的化石数量呈指数级增长，此类发现同步推动了学界对元古宙地球系统与化石产出地质背景（包括精度不断提升的年代约束）的认知深化。然而，针对元古宙环境变化与化石多样性之间关联的评估，却受限于诸多干扰因素，尤以岩性（lithological）偏差与埋藏学（taphonomic）偏差最为显著。在此，我们对当前元古宙地层中的真核生物化石记录进行汇编与分析，以期量化各类偏差的影响，并更精准地约束不同地质时期的多样性演化规律。我们的研究结果显示，元古宙时期群落内的平均多样性整体呈上升趋势，这源于