从未采样的幽灵群体中计算基因流动,同时估计进化历史
Arun Sethuraman1, Melissa Lynch2, Margaret Wanjiku1
1Department of Biology, San Diego State University, San Diego, California, USA 92182.
G3 (Bethesda, Md.)
|August 12, 2025
概括
从幽灵种群的基因流动可以偏向进化历史估计. 对这些未采样的人口进行核算对于准确的人口遗传学和人口建模至关重要.
科学领域:
- 人口基因组学 人口基因组学
- 进化生物学 进化生物学
- 生物信息学是一种生物信息学.
背景情况:
- 来自未采样或灭绝 ('幽灵') 种群的基因流可以在种群基因组数据中引入重大偏差.
- 这些偏见可能导致对进化历史的误解,影响人口结构和人口参数的估计.
- 现有的方法可能无法充分考虑这种"幽灵"种群对基因组分析的影响.
研究的目的:
- 从理论上建立和系统地评估由鬼群体的基因流引入的偏见.
- 评估幽灵种群对人口遗传学总结统计数据 (例如,π,FST,Tajima's D) 和人口历史推断 (例如,有效人口规模,分歧时间,迁移率) 的影响.
- 调查孤立与迁移 (IM) 模型在捕捉这些偏见方面的实用性,特别是在与最近人类进化相关的环境中.
主要方法:
- 对由幽灵种群基因流动引起的偏见的理论期望的发展.
- 在各种幽灵拓下进行广泛的模拟,以评估总结统计和人口统计模型中的偏差.
- 对来自非洲狩猎采集群体的355位元数据集进行分析,以检查现实世界的影响.
主要成果:
- 从幽灵种群的基因流动始终导致低估的分歧时间,高估的有效种群大小,以及低估的样本种群之间的迁移率.
- 像FST这样的总结统计数据被低估了,而当不考虑幽灵种群基因流动时,π被高估了.
- 最近的IM模型没有完全捕捉偏见,即使使用基于模型的人口历史估计,也强调了需要明确的幽灵人口建模.
结论:
- 如果不考虑未采样的幽灵种群的基因流动,可能会导致进化历史重建中的重大不准确性.
- 准确的人口统计推断需要明确考虑已灭绝或未采样的祖先种群的潜在贡献.
- 这些发现对理解人类进化有重要意义,特别是古老人类和现代人类之间的关系.
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