论文标题
原始甲烷循环生态系统以及早期地球大气和气候的共同进化
Coevolution of primitive methane cycling ecosystems and early Earth atmosphere and climate
论文作者
论文摘要
地球的历史是由代谢创新驱动的重大生态过渡的标志，从根本上重塑了海洋和大气的组成。最早的过渡的性质和幅度，即光合作用发展前数百万年，人们对此的理解仍然很差。使用新型的生态系统 - 生态系统模型，我们发现前甲烷 - 偶联微生物生态系统的生产力要比以前想象的要少得多。尽管生产力低，但甲烷作代代谢的演变仍强烈改变了大气成分，从而导致温暖但弹性较低的气候。随着非生物碳循环的反应，进一步的代谢进化（厌氧甲烷营养）可能会反馈到大气中并破坏气候的稳定，从而触发瞬时全球冰川。尽管早期的代谢进化可能会导致气候不稳定，但低CO：CH4大气比是在全球降低的行星上（如晚期的Hadean/早期大帝地球）上简单的甲烷循环生态系统的强大标志。
The history of the Earth has been marked by major ecological transitions, driven by metabolic innovation, that radically reshaped the composition of the oceans and atmosphere. The nature and magnitude of the earliest transitions, hundreds of million years before photosynthesis evolved, remain poorly understood. Using a novel ecosystem-planetary model, we find that pre-photosynthetic methane-cycling microbial ecosystems are much less productive than previously thought. In spite of their low productivity, the evolution of methanogenic metabolisms strongly modifies the atmospheric composition, leading to a warmer but less resilient climate. As the abiotic carbon cycle responds, further metabolic evolution (anaerobic methanotrophy) may feed back to the atmosphere and destabilize the climate, triggering a transient global glaciation. Although early metabolic evolution may cause strong climatic instability, a low CO:CH4 atmospheric ratio emerges as a robust signature of simple methane-cycling ecosystems on a globally reduced planet such as the late Hadean/early Archean Earth.
