Populating a Radiocarbon Database of North American, Phase II

University Of Wyoming, Laramie WY

Investigators

Abstract

Radiocarbon dating provides archaeologists with dates on organic materials (especially charcoal from hearths) that are less than 45,000 years old. It is the primary method that North American archaeologists use, and millions of dollars in federal and other funding has been spent in obtaining thousands of such dates from archaeological sites. Researchers around the world now use the changing abundance of radiocarbon dates as a way to reconstruct population histories over time, and thus to provide an important piece of human history: where and when did populations rise and decline? How fast? How does population change relate to climate change, technological innovation, population density, subsistence, warfare, and emigration, social and political organization? This project has already compiled dates from the 11 western U.S. states (35,000+); it will now move on to compile dates from the 11 plains states. It is not only the dates themselves that are compiled, but also associated contextual information that researchers need to "clean" the database to create a sample useful for their specific research questions. The data will become publically and freely available through the Canadian Archaeological Radiocarbon Database, a large and growing international radiocarbon database. It will provide researchers with a useful tool to investigate research questions in several disciplines including archaeology, paleontology, and genetics, and help move North American archaeology toward its next frontier, "Big Data," since archaeology's strength is its ability to test hypotheses against patterns in data across vast reaches of space and time. This project focuses on the question of prehistoric rates of population growth and, contrary to received wisdom, has already discovered that the long-term rates of growth of agricultural populations are the same as earlier hunting and gathering populations. If this discovery stands, it implies that the only significant change in human demographic history occurred in the nineteenth century, when technological advances in food production and trade coupled with advances in medical knowledge dramatically increased the rate of population growth. In other words, rapid population growth is only a feature of modern human life. To achieve this goal the project is investigating the "best practices" of statistical analysis of large samples of radiocarbon dates. Rises and declines in the number of dates per unit time is assumed to track similar rises and declines in human population. There is reason to be cautious as there are several variables that could modify if not negate this assumed relationship, for example, research bias, the systematic loss of dates over time due to preservation , and the effects of the standard procedure used to convert radiocarbon ages in familiar calendar dates.