细胞的起源和复杂性的增加与氧气的增加同步
Jack M Craig1,2,3, Sudhir Kumar1,2,3, S Blair Hedges1,2,3
1Center for Biodiversity, Temple University, Philadelphia, PA, United States.
Frontiers in bioinformatics
|September 20, 2023
概括
对于复杂生命至关重要的真核生物的起源现在估计在22亿至15亿年前,与增加的氧气水平保持一致. 这表明氧气推动了生物复杂性的兴起.
科学领域:
- 进化生物学 进化生物学
- 生物地质化学生物地质化学
- 分子遗传学分子遗传学
背景情况:
- 细胞的起源是生命历史上一个关键事件,但它的时间仍然不确定,影响我们对早期地球条件的理解.
- 以前对真核生物起源的分子钟估计有很大的差异 (2,1 - 0,91 亿年前) 并且经常与大氧化事件 (GOE) 相冲突.
研究的目的:
- 通过使用新的遗传数据和校准方法,完善真核生物起源的时间表.
- 研究真核生物进化,大气氧水平和生物复杂性的发展之间的关系.
主要方法:
- 利用了古生物学和细菌谱系的遗传数据,并结合了以前研究中较少使用的细菌数据.
- 采用了新的时间校准的基因分析分析,以避免影响以前分子时钟估计的偏差.
- 使用细胞类型,基因数和基因组大小,重建了生物复杂性的进化历史.
主要成果:
- 产生了新的,更精确的对真核生物起源的时间估计,将其置于22亿至15亿年前的保守间隔内,核心间隔为20亿至18亿年前.
- 这一修订的时间表与大气氧气上升的时期密切相关.
- 生物复杂性的增加,通过细胞类型,基因和基因组大小来衡量,暂时跟随并反映了氧气的增加.
结论:
- 精细的真核生物起源的时间支持氧气可用性增加和复杂生命的出现之间的强烈联系.
- 氧气可能提供了必要的能量来支持早期复杂的真核细胞的代谢需求.
- 这项研究突出了地化学事件和地球上主要的进化过渡之间的相互作用.
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