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

在美国国家科学基金会的支持下，丹尼斯·詹金斯、埃斯克·威勒斯列夫和布莱恩·肯普将召集一个由同事组成的国际团队，在俄勒冈州北部大盆地地区的佩斯利5英里角洞穴遗址继续进行考古、地质考古、古生态和古遗传学研究。这项研究的核心是对从现场找到的人类粪化石（干粪便）进行古遗传学（古代线粒体DNA）研究。该项目汇集了来自美国和国外多所大学（俄勒冈州、俄勒冈州立大学、加利福尼亚州、伯克利分校、华盛顿州和丹麦哥本哈根）的跨学科专家团队。基因研究通过提供与该地区从第一次占领到与欧洲美洲人的历史接触约14,300年的美洲原住民遗传史相关的新证据，解决了美洲第一次人类殖民研究的核心问题。1938年至1940年间，路德·s·克雷斯曼（Luther S. Cressman）对佩斯利洞穴遗址进行了初步调查，发现在一个小房子的地板上有更新世动物遗骸（灭绝的骆驼、马和野牛骨头）和石器制品。在克雷斯曼看来，这表明美洲原住民在更新世末期杀死并食用了这些动物。虽然承认证据相当有希望，但大多数考古学家并不接受克雷斯曼的佩斯利洞穴解释，因为缺乏足够的文献来说明文化和自然材料的联系和背景。俄勒冈大学（University of Oregon）在2002年、2003年和2007年对该遗址进行了新的调查，试图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之间的联系，来解决这一问题。含有古人类mtDNA的粪化石与更新世骆驼、马、野牛、鼠兔、鱼和水禽的骨骼在地层和空间上存在关联。通过放射性碳年代测定，粪化石和灭绝的动物遗骸在13100年至14300年前的年代上重叠。最早的粪化石比克洛维斯文化阶段早了1000多年。大约70年来，高度独特的克洛维斯技术一直被认为是北美最早可可靠识别的“文化”，主要是因为它与已灭绝的更新世巨型动物（如猛犸象和乳齿象）之间无可辩驳的联系，这些动物通过放射性碳测定可以追溯到13000多年前。因此，克洛维斯人一直是所有其他人类最早在西半球殖民的说法的比较标准。佩斯利洞穴的粪化石首次明确地将人类遗骸（DNA）与克洛维人之前灭绝的更新世动物联系在一起。从粪化石中恢复的古代线粒体DNA表明，它们是由属于A2和B2单倍群的人类产生的，这两种类型通常在亚洲/西伯利亚和美洲原住民人群中发现。然而，在回收或实验室取样过程中，粪化石受到现代DNA的污染，限制了许多标本的研究潜力。这种污染可以通过将较长的现代欧洲DNA链与较短的古代美洲原住民DNA链（部分分解）分离来过滤，但这种净化过程严重限制了对古代遗址居住者遗传历史的确定。新的佩斯利岩洞挖掘工作将由挖掘队穿着外科工作服（一次性工作服，头罩，面罩，乳胶外科手套和靴子套）进行，并采用新开发的现场和实验室规程，旨在防止现代DNA污染。粪化石将用无菌一次性镊子收集，并储存在无菌实验室标本罐中。未受污染的古印第安和全新世粪化石的恢复将使研究群体谱系、组成、健康、遗传多样性和饮食成为可能。遗传分析的结果将大大增加对古代亚洲/西伯利亚和现代美洲原住民之间古美洲遗传联系的认识。目前关于美洲第一次殖民的模型主要是基于对现代人口遗传多样性的研究，其次是稀疏的考古和古代DNA数据。这个项目将大大增加直接的遗传和考古数据，这是未来第一次殖民建模的基础。这将允许测试模型，例如主要基于现代DNA研究构建的白令陆桥孵化模型。这项提案资助的研究也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。该项目将为多个机构的研究生提供帮助，这突显了该项目更广泛的影响。俄勒冈大学在招收考古学、地理考古学和分子遗传学研究领域的印第安人方面有着既定的记录，尤其是克拉马斯部落。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UO， WSU和哥本哈根大学的研究生助理提供经济支持。

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.