Collaborative Research: Paleo Genetic Investigations at the Pre-Clovis Paisley Caves Site in the Northern Great Basin, Oregon

在国家科学基金会的支持下，丹尼斯·詹金斯博士、埃斯克·威勒斯列夫博士和布莱恩·肯普博士将召集一个国际同事团队，在俄勒冈州北部大盆地地区的佩斯利5英里点洞穴遗址继续进行考古、地质考古、古生态和古遗传学调查。这项研究的核心是对从该遗址发现的人类粪便(干粪便)的古遗传学(古代线粒体DNA)研究。该项目汇集了来自美国和外国大学(俄勒冈、俄勒冈州立大学、加利福尼亚州、伯克利、华盛顿州和丹麦哥本哈根)的跨学科专家团队。这项基因研究通过提供与该地区美洲原住民从第一次占领到与欧洲美洲人历史性接触的大约14,300年的遗传史有关的新证据，解决了研究美洲第一次人类殖民的核心问题。最初由路德·S·克雷斯曼在1938年至1940年间进行调查，佩斯利洞穴遗址被发现在一座小房子的地板上发现了更新世动物遗骸(已灭绝的骆驼、马和野牛的骨头)和石器文物。这向克雷斯曼暗示，美洲原住民在更新世末期杀死并吃掉了这些动物。虽然承认证据是相当有希望的，但大多数考古学家并不接受克雷斯曼的佩斯利洞穴的解释，因为缺乏足够的文件来说明文化和自然材料的联系和背景。俄勒冈大学对该遗址的最新调查(2002年、2003年和2007年)表明，通过应用现代挖掘技术和分析技术，更充分地记录文化材料与已灭绝的更新世动物遗骸的关系，试图解决这一问题。含有古人类mtDNA的粪岩在地层和空间上与更新世的骆驼、马、野牛、鼠兔、鱼和水禽的骨骼相关联。放射性碳测年证明，在13,100到14,300年前，粪便化石和灭绝的动物群遗骸在时间上是重叠的。最早的粪便化石比克洛维斯文化阶段早1000多年。70年来，极具特色的Clovis技术一直被认为是北美最早、最可靠的可识别的“文化”，主要是因为它与已灭绝的更新世大型动物--如猛犸象和乳齿象--有着无可辩驳的联系，根据放射性碳测年，这些大型动物的年代超过了13,000年。因此，克洛维斯一直是比较所有其他声称西半球最早的人类殖民的指标。佩斯利洞穴粪岩代表了人类遗骸(DNA)第一次明确地与早于克洛维斯的更新世灭绝动物联系在一起。从粪便化石中发现的古代线粒体DNA表明，它们是由属于单倍群A2和B2的人类产生的，这两种类型在亚洲/西伯利亚人和美洲原住民中很常见。然而，在回收或实验室采样过程中，粪便样本受到现代DNA的污染，限制了许多标本的研究潜力。这种污染可以通过从较短(部分分解)的古代美洲原住民DNA中分离出较长的现代欧洲DNA链来过滤掉，但这种净化过程严重限制了可以确定古代遗址居住者遗传史的因素。新的佩斯利洞穴挖掘将由穿着外科服装(戴着头巾、口罩、乳胶外科医生手套和靴子覆盖的一次性工作服)的挖掘小组进行，并采用新开发的现场和实验室方案来防止现代DNA污染。粪便将用无菌一次性钳子收集，并储存在无菌实验室标本瓶中。未受污染的古印度和全新世协长岩的恢复将使对群体谱系、成分、健康、遗传多样性和饮食的研究成为可能。基因分析的结果将显著增加对古代亚洲/西伯利亚人和现代美洲原住民之间的古美洲遗传联系的了解。目前美洲第一次殖民的模式主要是基于对现代人口遗传多样性的研究，其次是稀少的考古和古代DNA数据。该项目将大大增加直接的遗传和考古数据，作为未来第一次殖民的建模依据。这将允许对主要由现代DNA研究构建的贝林孵化模型等模型进行测试。根据这项建议资助的研究还将产生广泛适用于分子遗传学、考古学和古生态学领域的数据。该项目将向多个机构的研究生提供援助，这突出了该项目的更广泛影响。俄勒冈大学在招募在考古学、地质考古学和分子遗传学领域，特别是克拉马斯部落有既得利益的美洲原住民方面有着既定的记录。该项目包括实验室助理职位，以帮助分析、处理和管理收集以及数据管理，为华盛顿大学、密歇根州立大学和哥本哈根大学的研究生助理提供财政支持。

With National Science Foundation support, Drs. Dennis Jenkins, Eske Willerslev, and Brian Kemp will bring together an international team of colleagues to continue archaeological, geoarchaeological, paleo-ecological, and paleo-genetic investigations at the Paisley 5 Mile Point Caves site in the Northern Great Basin region of Oregon. Central to the research is paleo-genetic (ancient mitochondrial DNA) research on human coprolites (dried feces) recovered from the site. The project brings together an inter-disciplinary team of specialists from various U.S. and foreign Universities (Oregon, Oregon State, California, Berkley, Washington State and Copenhagen, Denmark). The genetic research addresses issues central to the study of the first human colonization of the Americas by providing new evidence related to the genetic history of Native Americans in the region spanning some 14,300 years from first occupation to historic contact with Euroamericans. Initially investigated by Luther S. Cressman between 1938 and 1940, the Paisley Caves site was found to contain Pleistocene faunal remains (extinct camel, horse, and bison bones) mixed with stone artifacts on a small house floor. This suggested to Cressman that Native Americans had killed and eaten these animals at the end of the Pleistocene. While admitting the evidence was quite promising, most archaeologists have not accepted Cressman's Paisley Caves interpretation due to the lack of adequate documentation for the association and context of the cultural and natural materials. New investigations of the site by the University of Oregon (2002, 2003 and 2007) represented an attempt to resolve this issue through more adequate documentation of the association of cultural materials with extinct Pleistocene animal remains by the application of modern excavation techniques and analytical technologies. Coprolites containing ancient human mtDNA were recovered in stratigraphic and spatial association with Pleistocene camel, horse, bison, pika, fish, and water fowl bones. The coprolites and extinct faunal remains proved by radiocarbon dating to chronologically overlap between 13,100 and 14,300 years ago. The earliest coprolites predate the Clovis cultural phase by more than 1,000 years. The highly distinctive Clovis technology has been recognized as the earliest reliably identifiable "culture" in North America for some 70 years, primarily because of its irrefutable association with extinct Pleistocene megafauna -such as mammoths and mastodons -dated by radiocarbon to more than 13,000 years. Thus, Clovis has been the measure by which all other claims for earliest human colonization of the Western Hemisphere have been compared. The Paisley Caves coprolites represent the first time that human remains (DNA) have clearly been associated with extinct Pleistocene animals in a context predating Clovis. Ancient mitochondrial DNA recovered from the coprolites indicates that they were produced by humans belonging to haplogroups A2 and B2, types commonly found among Asian/Siberian and Native American populations. However, contamination of the coprolites with modern DNA during the recovery or lab sampling process limits the research potential of many specimens. This contamination can be filtered out by separating longer strands of modern European DNA from the shorter (partially decomposed) strands of ancient Native American DNA but this decontamination process severely limits what can be determined about the genetic history of the ancient site occupants.The new Paisley Caves excavations will be conducted by excavation teams wearing surgical garb (disposable coveralls with head covering, face mask, latex surgeon's gloves, and boot coverings) and employing newly developed field and laboratory protocols designed to protect against modern DNA contamination. Coprolites will be collected with sterile disposable forceps and stored in sterile lab specimen jars. The recovery of uncontaminated Paleoindian and Holocene coprolites will allow research into group lineages, composition, health, genetic diversity, and diet. The results of the genetic analysis will significantly increase knowledge of Paleoamerican genetic connections between ancient Asian/Siberian and modern Native American populations. Current models of the first colonization of the Americas are primarily based on the study of genetic diversity among modern populations, and only secondarily on sparse archaeological and ancient DNA data. This project will significantly increase the direct genetic and archaeological data on which future modeling of the first colonization is based. This will allow testing of models such as the Beringian Incubation Model constructed predominantly from modern DNA studies. The research funded under this proposal will also generate data broadly applicable to the fields of molecular genetics, archaeology, and paleo-ecology. The broader implications of this project are highlighted by the assistance the project will provide graduate students at multiple institutions. The University of Oregon has an established record in the recruitment of Native Americans with a vested interest in the fields of archaeology, geoarchaeology, and molecular genetic studies, particularly The Klamath Tribes. Laboratory assistant positions to aid in the analysis, handling and management of collections, and data management are included in the project to provide financial support for graduate student assistants at the UO, WSU, and the University of Copenhagen.