Li Chao, Cheng Meng, Zhu Maoyan, Lyons Timothy W
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
State Key Laboratory of Palaeobiology and Stratigraphy and Center for Excellence in Life and Paleoenvironment, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.
Emerg Top Life Sci. 2018 Sep 28;2(2):279-288. doi: 10.1042/ETLS20170157.
It is generally agreed that early diversification of animals and significant rise of atmospheric and oceanic oxygen (O2) levels occurred in the Ediacaran (635-541 million years ago, Ma) and early Cambrian (ca. 541-509 Ma). The strength and nature of their relationship, however, remain unclear and debated. A recent wave of paleoredox research - with a particular focus on the fossiliferous sections in South China - demonstrates high spatial heterogeneity of oceanic O2 (redox) conditions and dynamic marine shelf oxygenation in a dominantly anoxic ocean during the Ediacaran and early Cambrian. This pattern shows a general spatiotemporal coupling to early animal evolution. We attribute dynamic shelf oxygenation to a complex interplay among the evolving atmosphere, continents, oceans, and biosphere during a critical period in Earth history. Our review supports the idea of a complex coevolution between increasing O2 levels and early diversification of animals, although additional work is required to fully delineate the timing and patterns of this coevolution and the mechanistic underpinnings.
人们普遍认为，动物的早期多样化以及大气和海洋中氧气（O₂）水平的显著上升发生在埃迪卡拉纪（6.35 - 5.41亿年前，Ma）和寒武纪早期（约5.41 - 5.09 Ma）。然而，它们之间关系的强度和性质仍不明确且存在争议。最近一波古氧化还原研究——特别关注中国南方的含化石地层——表明，在埃迪卡拉纪和寒武纪早期，海洋O₂（氧化还原）条件具有高度的空间异质性，且在以缺氧为主的海洋中，陆架海洋的氧化作用具有动态变化。这种模式显示出与早期动物进化存在普遍的时空耦合关系。我们将陆架动态氧化作用归因于地球历史关键时期不断演化的大气、大陆、海洋和生物圈之间复杂的相互作用。我们的综述支持氧气水平上升与动物早期多样化之间存在复杂共同进化的观点，尽管还需要更多工作来全面描绘这种共同进化的时间和模式以及其机制基础。
