Populating a Radiocarbon Database of North American, Phase II

放射性碳测年为考古学家提供了不到45000年的有机材料(特别是壁炉中的木炭)的年代。这是北美考古学家使用的主要方法，已经花费了数百万美元的联邦和其他资金从考古遗址获得数千个这样的年代。世界各地的研究人员现在利用放射性碳测年丰度的变化来重建随着时间推移的人口历史，从而提供一段重要的人类历史：人口在哪里以及何时上升和下降？多快？人口变化与气候变化、技术创新、人口密度、生存、战争和移民、社会和政治组织有何关系？这个项目已经汇编了美国西部11个州(35,000个)的日期；现在它将继续汇编11个平原州的日期。研究人员不仅需要汇编日期本身，还需要相关的上下文信息来“清理”数据库，以创建对他们的特定研究问题有用的样本。这些数据将通过加拿大考古放射性碳数据库向公众免费提供，该数据库是一个大型且不断增长的国际放射性碳数据库。它将为研究人员提供一个有用的工具来研究包括考古学、古生物学和遗传学在内的几个学科的研究问题，并帮助北美考古学走向它的下一个前沿--“大数据”，因为考古学的优势是它有能力根据广阔的空间和时间范围的数据模式来测试假设。这个项目专注于史前人口增长率的问题，与公认的智慧相反，它已经发现农业人口的长期增长率与早期狩猎和采集人口的速度相同。如果这一发现成立，它意味着人类人口历史上唯一重大的变化发生在19世纪，当时食品生产和贸易的技术进步，加上医学知识的进步，极大地提高了人口增长的速度。换句话说，人口的快速增长只是现代人类生活的一个特征。为了实现这一目标，该项目正在调查对大样本放射性碳测年进行统计分析的“最佳做法”。每单位时间约会次数的上升和下降被认为与人类人口的上升和下降类似。有理由保持谨慎，因为有几个变量可能会修改或否定这一假定的关系，例如，研究偏差、由于保存而导致的系统性日期损失，以及在熟悉的日历日期中转换放射性碳年龄所使用的标准程序的影响。

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.