The long history of life on Earth has unfolded as a cause-and-effect relationship with the evolving amount of oxygen (O₂) in the oceans and atmosphere. Oxygen deficiency characterized our planet's first 2 billion years, yet evidence for biological O₂ production and local enrichments in the surface ocean appear long before the first accumulations of O₂ in the atmosphere roughly 2.4 to 2.3 billion years ago. Much has been written about this fundamental transition and the related balance between biological O₂ production and sinks coupled to deep Earth processes that could buffer against the accumulation of biogenic O₂. However, the relationship between complex life (eukaryotes, including animals) and later oxygenation is less clear. Some data suggest O₂ was higher but still mostly low for another billion and a half years before increasing again around 800 million years ago, potentially setting a challenging course for complex life during its initial development and ecological expansion. The apparent rise in O₂ around 800 million years ago is coincident with major developments in complex life. Multiple geochemical and paleontological records point to a major biogeochemical transition at that time, but whether rising and still dynamic biospheric oxygen triggered or merely followed from innovations in eukaryotic ecology, including the emergence of animals, is still debated. This paper focuses on the geochemical records of Earth's middle history, roughly 1.8 to 0.5 billion years ago, as a backdrop for exploring possible cause-and-effect relationships with biological evolution and the primary controls that may have set its pace, including solid Earth/tectonic processes, nutrient limitation, and their possible linkages. A richer mechanistic understanding of the interplay between coevolving life and Earth surface environments can provide a template for understanding and remotely searching for sustained habitability and even life on distant exoplanets.

中文翻译：

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地球中期历史中的氧合、生命和行星系统：概述

地球上生命的悠久历史已经展现为与海洋和大气中不断变化的氧气 (O ₂ )量的因果关系。缺氧是我们星球最初 20 亿年的特征，但在大约 2.4 到 23 亿年前，早在大气中 O ₂首次积累之前，就出现了海洋表层生物 O _{2产生和局部富集的证据。关于这一基本转变以及生物 O 2}产生和与地球深部过程耦合的相关平衡，可以缓冲生物源 O _{2的积累，已经写了很多文章。}. 然而，复杂生命（包括动物在内的真核生物）与后期氧合之间的关系尚不清楚。一些数据表明，O ₂较高，但在接下来的 10 亿年半中仍处于较低水平，然后在大约 8 亿年前再次增加，这可能为复杂生命的初始发展和生态扩张设定了一条具有挑战性的路线。_{O 2}明显升高大约 8 亿年前，与复杂生命的重大发展相吻合。多个地球化学和古生物学记录表明当时发生了重大的生物地球化学转变，但仍然存在上升和仍然动态的生物圈氧气是否触发或仅仅跟随真核生态学的创新，包括动物的出现，仍然存在争议。本文重点关注大约 1.8 到 5 亿年前地球中期历史的地球化学记录，作为探索与生物进化的可能因果关系以及可能决定其步伐的主要控制因素的背景，包括固体地球/构造过程、养分限制及其可能的联系。