一个结构化融合模型揭示了所有现代人类共同的深层祖先结构
Trevor Cousins1, Aylwyn Scally1, Richard Durbin2
1Department of Genetics, University of Cambridge, Cambridge, UK.
Nature genetics
|March 19, 2025
概括
现代人类的起源涉及古老的混合事件. 一个新的模型揭示了两种祖先群体在30万年前混合在一起,其中一个祖先群体与尼安德特人和丹尼索瓦人有关.
科学领域:
- 人类进化遗传学人类进化遗传学
- 人口遗传学 人口遗传学
- 古代DNA分析 古代DNA分析
背景情况:
- 了解人类起源需要分析混合事件和人口规模变化.
- 基于凝聚的模型对于推断人口历史至关重要.
- 以前的模型在表示复杂的祖先人口动态方面存在局限性.
研究的目的:
- 为了介绍一种基于凝聚的新型隐藏马尔科夫模型,cobraa.
- 为了明确地建模祖先人口分裂和重新加入事件.
- 将模型应用于跨物种的模拟和真实基因组数据.
主要方法:
- 开发cobraa,一个基于凝聚的隐藏马尔科夫模型.
- 应用cobraa对模拟数据集进行验证.
- 分析来自多个物种,包括现代人类的真实基因组数据.
主要成果:
- 现代人类历史上长期存在结构的证据.
- 大约在30万年前,两个祖先群体之间的混合事件发生在80:20的比率下.
- 在分歧后不久,在主要的祖先群体中检测到一个强大的瓶.
- 来自少数族裔祖先群体的基因组区域与编码序列的距离相关,这表明了负选择.
- 大多数祖先地区与人类-古人类分歧有很强的相关性,表明其与尼安德特人和丹尼索瓦人有祖先的联系.
结论:
- 这项研究提供了一个新的计算工具 (cobraa) 用于详细的人口推断.
- 现代人类是从一个有结构的祖先群体进化而来的,有着重要的混合事件.
- 这些发现揭示了塑造人类基因组的进化压力和祖先组成部分,包括与古老人类的联系.
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