在考古时期,平行地适应高温
Bastien Boussau1, Samuel Blanquart, Anamaria Necsulea
1Laboratoire de Biométrie et Biologie Evolutive, CNRS, Université de Lyon, Université Lyon I, 43 Boulevard du 11 Novembre, 69622 Villeurbanne, France.
Nature
|November 28, 2008
概括
最后一个普遍的共同祖先 (LUCA) 很可能是中性,细菌和古生物-真核生物的祖先后来趋同地适应了高温. 然后,热耐受性在这些血统中随着进化时间的推移而下降.
科学领域:
- 进化生物学 进化生物学
- 基因组学就是基因组学.
- 生物化学 生物化学
背景情况:
- 解释早期生命化石是具有挑战性的,需要使用替代方法来研究祖先生态.
- 现存基因组中的遗传足迹提供了对祖先生物温度的见解.
- 以前的研究产生了关于最后一个普遍共同祖先 (LUCA) 的热环境的相互矛盾的假设.
研究的目的:
- 用分子数据研究早期生命的热进化.
- 为了协调关于LUCA温度和祖先耐热性的相互矛盾的发现.
- 重建生命树早期的温度适应阶段.
主要方法:
- 对核糖体RNA (rRNA) 和蛋白质序列的分析.
- 应用先进的,现实的分子进化模型.
- 基于基因组数据的祖先热适应的重建.
主要成果:
- 有证据支持两个不同的与温度相关的进化阶段.
- 热耐受性从一个半性LUCA增加到热性细菌和古生物-真核生物祖先.
- 热耐受性随后下降,表明对高温的适应趋同.
结论:
- 卢卡很可能是介质性,而不是热性.
- 细菌和Archaea-Eukaryota的祖先融合适应高温,可能是由于气候变化或基因组过渡.
- 这项研究为早期生命的热进化提供了一个统一的观点.
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