Calibrating the Early Peopling of North America: Ancient Biomolecular and Chronological Contexts

在美国国家科学基金会的支持下，加州大学河滨分校的R.E.Taylor博士和加州大学戴维斯分校的David Smith博士将利用加速器质谱仪技术进行放射性碳(14C)测量，并检测来自北美15个地点的35个人类骨骼样本的线粒体DNA(MtDNA)含量，这些样本的指示年龄约为5,000至11,000年。合作者实验室最近开发的技术能力将提供数据，以解决最近因北美几具人类骨骼的异常物理特征而提出的问题，这些骨骼可以追溯到全新世早期--在1万到6000年前。14C数据将提供时间控制，mtDNA数据将定义所检查的一组人类骨骼样本之间的遗传关系。这项研究的目的是考察最近提出的各种问题，涉及对最早的人类在更新世末期和全新世开始时从亚洲迁移到北美的时间和特征的新理解。狩猎者和采集者群体的这种运动构成了人类物种历史上最重大的迁徙之一。它发生的确切时间和方式一直是科学家们长期争论的话题，有时甚至是有争议的。根据来自北美和南美洲几个地点的数据，长期以来认为更新世晚期北美克洛维斯文化代表着新大陆最早的人类占领的观点受到了挑战。这一数据似乎表明，在北美克洛维斯占领的最早表现形式之前，至少1000年前，新大陆就有人类群体的存在。此外，对最近归属于全新世早期的一些北美人类骨骼的物理特征的初步评估表明，美洲原住民祖先群体的起源可能比目前所了解的要复杂得多。一系列早期的多次迁徙可能在北美产生了非常复杂的晚更新世/早全新世的遗传混合。这项研究中将获得的数据将直接解决的一个主要研究问题是，一些早期北美人类群体是否没有幸存下来，因此可能与任何当代美洲原住民群体没有遗传关系。

With the support of the National Science Foundation, Dr. R. E. Taylor (University of California, Riverside) and Dr. David Smith (University of California, Davis) will undertake radiocarbon (14C) measurements using accelerator mass spectrometry technology and examine the mitochondrial DNA (mtDNA) content in a group of 35 human skeletal samples from 15 North America sites with indicated ages ranging from approximately 5,000 to 11,000 years. Recently developed technical capabilities in the laboratories of the collaborators will provide data to address questions recently raised by what appears to be anomalous physical characteristics of several North American human skeletons dating to the early Holocene--between 10,000 and 6,000 years ago. The 14C data will provide the temporal controls and the mtDNA data will define genetic relationships between and among the group of human skeletal samples examined. The purpose of this research is to examine various questions that have recently been posed involving new understandings concerning the timing and character of earliest human migrations from Asia to North America at the very end of the Pleistocene and beginning of the Holocene. This movement of hunter and gatherer groups constitutes one of the most significant migration in the history of the human species. Precisely when and how it occurred have been the subject of long standing and sometimes contentious debates among scientists. The long-held view that the late Pleistocene North American Clovis culture represented the earliest New World human occupation has been challenged on the basis of data from several sites in both North and South America. This data appears to point to the presence of human groups in the New World at least 1,000 years prior to the earliest manifestation of Clovis occupation in North America. In addition, preliminary evaluations of physical characteristics of a number of North American human skeletons recently assigned to the early Holocene suggest that the origins of the ancestral populations of Native Americans may be much more complex than currently understood. A series of early multiple migrations may have produced a very complex late Pleistocene/early Holocene genetic admixture in North America. A major research question that will be directly addressed with the data to be obtained in this study is whether some early North American human populations did not survive and thus may not be genetically related to any contemporary Native American group.