NSF Postdoctoral Fellowship in Biology FY 2021: Understanding the Demographic History of Populations using Identity-by-Descent

该行动资助2021财年美国国家科学基金会生物学博士后研究奖学金，扩大生物学中代表性不足群体的参与。该奖学金支持该研究员的一项研究和培训计划，该计划将增加生物学中代表性不足的群体的参与。该项目将拓展该研究员的数学技能，并将推进该研究员在基因组学领域未被充分研究的人口构成方面的研究。该项目的目标是提供关于影响人类基因组中不同类型共享基因组片段的历史过程的见解。特别是，这项工作旨在通过使用数学和统计模型，加深对非裔美国人人口和遗传历史在基因组学领域的认识。该研究员的工作有助于增加基因组学中不同人群的代表性，并解决当前基因组学数据集的不平衡问题。该项目将促进研究员在斯坦福博士后社区的教学、指导和工作方面的活动。该项目将扩展该研究员以前的研究，同时使该研究员能够发展理论种群遗传学和随机模拟方面的技能。该项目将提供关于影响人类基因组中纯合子（ROH）和同血统（IBD）片段长度分布的潜在人口统计过程的见解，并将提供有关混合种群的历史相关信息。首先，实时前向模拟将用于生成人口历史谱，以确定IBD和ROH的预期长度分布和基因组负担。接下来，模拟模型将应用于经验数据，以评估模型的准确性，并评估未充分研究人群的可能的人口统计历史。最后，该研究员将使用混合的机制模型来估计来自源群体的不同谱系祖先的数量，这些祖先需要在混合个体中产生当前的混合分数。该混合模型将应用于非裔美国人群体，以估计对现代混合个体基因组做出贡献的非洲和欧洲个体的预期数量。该项目将通过使用数学模型来了解人口如何随着时间的推移而进化，并了解作用于现代基因组的进化力量，从而将人类学、生物学和统计学领域联系起来。除了学术研究外，该研究员还将继续教学，通过指导与其他在STEM领域未被充分代表的学生建立关系，并积极参与斯坦福大学的多元化努力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Broadening Participation of Groups Under-represented in Biology. The Fellowship supports a research and training plan for the fellow that will increase the participation of groups underrepresented in biology. This project will expand the fellow’s skills in mathematics and will advance the fellow’s research on understudied population makeup in the field of genomics. The goals of this project are to deliver insights about the historical processes that affect different types of shared genomic segments in the human genome. In particular, this work seeks to deepen knowledge of African American demographic and genetic history in the field of genomics by using mathematical and statistical models. The fellow’s work contributes to increasing the representation of diverse populations in genomics, and addressing imbalances in current genomics data sets. The project will promote the fellow’s activities in teaching, mentoring, and working within the Stanford postdoctoral community.This project will expand upon the fellow’s previous research, while enabling the fellow to develop skills in theoretical population genetics and stochastic simulation. The project will deliver insights about the underlying demographic processes that affect the length distribution of runs of homozygosity (ROH) and identical-by-descent (IBD) segments in the human genome, and it will provide historically relevant information about admixed populations. First, forward-in-time simulations will be used to generate a spectrum of demographic histories to determine the expected length distribution and genomic burden of IBD and ROH. Next, the simulated models will be applied to empirical data to assess model accuracy and to assess possible demographic histories of understudied populations. Lastly, the fellow will use a mechanistic model of admixture to estimate the number of distinct genealogical ancestors from a source population that are required to generate current admixture fractions in an admixed individual. This admixture model will be applied to African American populations to estimate the expected number of African and European individuals that contributed to the genomes of modern admixed individuals. This project will bridge the fields of anthropology, biology, and statistics by using mathematical models to understand how populations evolve over time and to understand the evolutionary forces acting on modern genomes. In addition to academic research, the fellow will continue teaching, cultivating relationships with other underrepresented students in STEM through mentorship, and active participation in diversity efforts at Stanford.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.