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

University Of California-Riverside, Riverside CA

Investigators

Abstract

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.