全球共同祖先理论的正式测试
1Department of Biochemistry, Brandeis University, Waltham, Massachusetts 01778, USA. dtheobald@brandeis.edu
Nature
|May 14, 2010
概括
这项研究为普遍共同祖先 (UCA) 提供了第一个正式的定量测试,证实地球上的所有生命都有一个单一的起源. 对保存蛋白质的统计分析压倒性地支持UCA,即使是横向基因转移.
科学领域:
- 进化生物学 进化生物学
- 遗传学 是一个遗传学.
- 人类遗传学 是一个学科.
背景情况:
- 普世共同祖先 (UCA) 是进化论的一个基本概念,表明所有生命都来自单一的祖先物种.
- 以前的UCA证据在很大程度上是"本地"的,缺乏与现代遗传学和概率学方法的整合.
- 担心在生命早期的横向基因转移已经挑战了所有生命的单性.
研究的目的:
- 进行第一个普遍共同祖先 (UCA) 的正式,定量测试.
- 在不假定序列相似性的情况下评估UCA意味着直接的遗传亲属关系.
- 从统计学上评估所有已知的生命的单.
主要方法:
- 将模型选择理论应用于分子族系学.
- 专注于一组无处不在的保存蛋白质,被提出为正义的.
- 对比UCA模型与主要分类群体独立祖先的多个模型.
主要成果:
- 模型选择测试压倒性地支持了普遍的共同祖先模型.
- 尽管考虑了横向基因转移和共生融合事件,但这种支持仍然很强大.
- 这些发现为所有已知的陆地生物的单性提供了强有力的统计证据.
结论:
- 这项研究提供了对普遍共同祖先的首次严格统计验证.
- 所有生命的单一性都得到了强烈的支持,不管水平基因转移等复杂性如何.
- 这项工作加强了UCA作为现代进化理论的核心,经验验证的支柱.
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