The Impact of European Contact on Native American Evolutionary History

欧洲接触对美洲原住民进化史的影响

• 批准号: 1408876
• 负责人: Deborah Bolnick
• 金额: $ 21.17万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1408876&HistoricalAwards=false
• 关键词: Impact; European; Contact; Native; American

The objective of this Fellowship project is to investigate the impact of European contact (EC) on Native American genomic diversity by analyzing genome-wide diversity patterns in contemporary and ancient Native Americans from the southern US. Many genetic studies have investigated the origins and early history of Native Americans, but comparatively little attention has been given to recent evolutionary history and the impact that selection, migration, and genetic drift have had on Native American genomic diversity over the last five centuries. However, since European Contact, Native Americans have experienced repeated epidemics, demographic collapse, and genetic exchange (admixture) with non-native peoples. It is critical that we test whether and how each of these events reshaped the genetic structure of indigenous populations if we are to accurately reconstruct Native American evolutionary history and account for population genetic structure in other studies. In addition, this project provides research and training opportunities for a female Hispanic postdoctoral researcher to develop the technical and process skills necessary for her to succeed in science and in academia. The project also provides research experience and mentoring for students from underrepresented groups, including some from participating Native American communities. Additionally, this project formulates a community-based participatory research model for future genetic studies, and it integrates education and research through extensive outreach to indigenous communities.While some research suggests that admixture and the population collapse after EC influenced Native American genetic diversity, no study has fully assessed the genetic changes that occurred after EC. Existing datasets are insufficient for this purpose because few studies have examined genome-wide variation and relatively few pre-EC samples have been analyzed. Because of these limitations, we know remarkably little about the genetic makeup of Native American populations or about the genetic impact of European Contact. This project overcomes these deficiencies and has two major research goals: (1) assess the genomic diversity in pre-EC and contemporary (post-EC) Native North Americans, and (2) evaluate the genetic impact of EC by measuring the effects of post-EC demographic collapse, selection, and admixture. This project uses newly developed microarray and next-generation sequencing technologies and implement a novel comparative approach. The PI-team analyzes 629,443 genome-wide SNPs to evaluate diversity patterns in a post-EC population. They also analyze ~370,000 of the same SNPs in ancient DNA samples from pre-EC burial populations in the same geographic region to track changes in the Native American gene pool over time. This study focuses on contemporary and ancient populations from the southern US, where EC first occurred in North America. This project is designed to produce a dataset that is unprecedented in combining genome-wide coverage with population samples spanning a wide temporal range. With this dataset, it will become possible to measure the effects of drift, selection, and admixture following EC, providing the first comprehensive test of the hypothesis that EC reshaped the genetic structure of Native American populations. This project has the potential to transform our understanding of Native American genetic diversity and evolutionary history in the southern US, and improve our ability to account for current population genetic structure in disease association studies. It can also inform our understanding of how sociocultural change influences the human genome.

该奖学金项目的目标是通过分析美国南部当代和古代美洲原住民的基因组多样性模式，研究欧洲接触（EC）对美洲原住民基因组多样性的影响。许多遗传学研究调查了美洲原住民的起源和早期历史，但相对而言，很少有人关注最近的进化史，以及过去五个世纪中选择、迁移和遗传漂变对美洲原住民基因组多样性的影响。然而，自从与欧洲人接触以来，美洲原住民经历了反复的流行病、人口崩溃以及与非原住民的基因交换（混合）。如果我们要准确地重建美洲原住民的进化史，并在其他研究中解释群体遗传结构，那么测试这些事件是否以及如何重塑土著群体的遗传结构是至关重要的。此外，该项目还为一名西班牙裔女性博士后研究人员提供了研究和培训机会，以培养她在科学和学术界取得成功所需的技术和工艺技能。该项目还为来自代表性不足群体的学生提供研究经验和指导，包括一些来自参与的美洲原住民社区的学生。此外，该项目为未来的遗传研究制定了一个以社区为基础的参与性研究模式，并通过广泛接触土著社区，将教育和研究结合起来。虽然一些研究表明，欧共体迁移后的混合和种群崩溃影响了美洲原住民的遗传多样性，但没有研究充分评估欧共体迁移后发生的遗传变化。现有的数据集不足以达到这一目的，因为很少有研究检查了全基因组变异，并且分析了相对较少的ec前样本。由于这些限制，我们对美洲土著人口的基因构成或与欧洲人接触对基因的影响知之甚少。本项目克服了这些不足，有两个主要的研究目标：(1)评估前欧共体和当代（后欧共体）北美原住民的基因组多样性；(2)通过测量后欧共体人口崩溃、选择和混合的影响来评估欧共体的遗传影响。该项目采用新开发的微阵列和下一代测序技术，并实现了一种新的比较方法。pi团队分析了629443个全基因组snp，以评估后ec人群的多样性模式。他们还分析了来自同一地理区域前欧共体埋葬人群的古代DNA样本中的约37万个相同的snp，以追踪美洲原住民基因库随时间的变化。这项研究的重点是来自美国南部的当代和古代人群，在那里EC首次出现在北美。该项目旨在建立一个前所未有的数据集，将全基因组覆盖与跨越广泛时间范围的人口样本相结合。有了这个数据集，就有可能测量EC之后的漂移、选择和混合的影响，为EC重塑美洲原住民种群遗传结构的假设提供第一个全面的测试。这个项目有可能改变我们对美国南部印第安人遗传多样性和进化历史的理解，并提高我们在疾病关联研究中解释当前人群遗传结构的能力。它还可以让我们了解社会文化变化如何影响人类基因组。