Genetic evidence on the deep history of human populations

最近的研究表明，现代人携带的DNA来自远古的古人类，如尼安德特人和丹尼索瓦人。该项目将利用基因数据，结合一种新开发的统计方法，研究人类及其近亲在过去200万年中的历史。研究结果将告诉我们种群在分离后发生生殖隔离的速度。保护生物学家将对这些方法感兴趣，他们必须估计杂交的比率，以决定一个物种是否值得保护。研究结果对医学研究人员也很有用，因为他们在研究遗传疾病的原因时必须控制历史的影响。该项目将支持研究生培训，以及一个研讨会，该研讨会将培训来自美国各地的遗传学家在生物信息学和计算遗传学方面的方法，并支持扩大STEM研究的参与。现代人携带着过去与尼安德特人和丹尼索瓦人混合的基因特征。研究也记录了种群规模非常小的情况，在这种情况下，自然选择是无效的，有害的突变能够积累。然而，由于所使用的统计方法的局限性，我们对这些事件的理解是不完整的。目前的项目将使用一种新的方法，它纠正了这些问题，并使我们能够更深入地了解过去。它将(1)估计亚洲和大洋洲几个人群中丹尼索瓦人DNA的比例；(2)研究现代人与“超级古代人”的杂交，“超级古代人”在人属历史的早期与其他人族分离；(3)检验中东人群从一个假设的“基础欧亚人”人群中获得基因流的假设，该人群在欧洲人与东亚人分离之前从其他欧亚人中分离出来。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。

Recent research has shown that modern humans carry DNA derived from archaic hominin populations, such as Neanderthals and Denisovans, in the distant past. This project will use genetic data, together with a newly-developed statistical method, to study the history of humans and their close relatives during the past two million years. The results will inform us about the speed with which populations become reproductively isolated after separation. The methods will be of interest to conservation biologists, who must estimate rates of interbreeding in order to decide whether a species deserves protected status. The results also will be useful to medical researchers who must control for the effects of history as they study the causes of genetic disease. The project will support graduate training, as well as a workshop that will train geneticists from throughout the US in methods of bioinformatics and computational genetics and support efforts to broaden participation in STEM research.Modern humans carry genetic signatures of past admixture with Neanderthals and Denisovans. Research has also documented episodes of very small population size, during which natural selection was ineffective, and harmful mutations were able to accumulate. Our understanding of these events is incomplete however, because of limitations in the statistical methods used. The current project will use a new method, which corrects these problems and allows us to see farther into the past. It will (1) estimate the fraction of Denisovan DNA in several human populations of Asia and Oceania; (2) study interbreeding between modern humans and “superarchaics,” who separated from other hominins early in the history of the genus Homo; and (3) test the hypothesis that Middle Eastern populations received gene flow from a hypothetical population of “basal Eurasians,” which separated from other Eurasians before the separation of Europeans from East Asians.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.