在Archaean的有氧呼吸?
1Department of Paleobiolgoy, Smithsonian Institution, Washington, DC 20560, USA.
Nature
|November 1, 1990
概括
早期的地球地球.
科学领域:
- 地质化学 地质化学
- 大气科学 大气科学
- 古生物学的古生物学
背景情况:
- 人们普遍认为,阿基亚时代 (3.800-2.500亿年前) 的大气是无氧的.
- 像溶解铁 (Fe(II)) 氧化和甲氧化等氧气沉不足以维持无氧.
- 低估值的阿基亚人的初级生产力挑战现有的大气氧气调节模型.
研究的目的:
- 为了调查早期的有氧呼吸在Archaean Eon的可信性.
- 提出一种替代机制来调节大气中的氧气水平在原生代之前.
主要方法:
- 基于古老岩石中保存的有机碳重新评估氧气沉积点.
- 铁和甲氧化要求的建模,以维持无氧.
- 假设有氧呼吸的早期发展.
主要成果:
- 维持无氧需要不切实际的高铁沉积或甲氧化.
- 即使是最小的初级生产率也表明,氧气积聚的水槽不足.
- 研究表明,需要一个稳定的,低氧气大气 (0.2-0.4%).
结论:
- 有氧呼吸很可能在古老时期的早期演变.
- 早期的有氧呼吸可以防止大气中过度的氧气积累.
- 这挑战了对严格无毒的阿凯亚大气的传统观点.
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