Archaeology, through reconstruction of past behaviors and how they emerge and adapt over time, has the potential to provide insight into processes which shape human behavior and social organization today. To accomplish this goal it is necessary to have robust analytic tools which permit researchers to move from objects excavated from the ground to conclusions regarding the behaviors of people responsible for their discard. This project is important because it assists in developing such techniques.
With National Science Foundation support, Dr. Tammy Buonasera will begin a series of experiments using replicas of prehistoric ground stone milling tools (manos and metates and mortars and pestles) to generate empirically informed models of ground stone processing efficiency. These models will help evaluate relationships between ground stone technology, mobility, and resource use among prehistoric hunter-gatherers. The significance of the project rests on its potential to increase knowledge of economic decisions made by individuals engaged in plant food processing. In many contexts around the world, changes in the form and frequency of ground stone milling tools play key roles in reconstructing sequences of resource intensification, sedentism, and plant domestication. Despite this, there are few empirically grounded comparisons of the relative efficiency of different milling tool-resource combinations in the literature. Rather, links between form and function typically rest on commonsense notions of efficiency or "suitability." This study will provide better estimates than we now have for defining when it would be profitable to shift between grinding technologies, and results will be widely applicable to studies of ground stone function and resource use in many places and times.
The proposed project will begin with a series of controlled experiments designed to measure and compare the efficiency of five different forms (three mortar and two metate shapes), and two different raw materials (a harder and a softer stone), for processing four resources with different physical characteristics (acorns, small hard seeds, tule roots, and ocher). Because this research aims to provide data for modeling tool design choices among hunters and gatherers with varying degrees of mobility (i.e., from conditions of high residential mobility, where food is not stored, to semi-sedentary contexts, where food storage may be critical), experiments will also compare grinding efficiency and use-wear patterns for fresh and dried versions of the plant resources (acorns, small hard seeds, tule roots). Simple optimization models will be used to compare experimental estimates of food processing labor and costs of tool manufacture against overall productivity. Ultimately, this research will improve knowledge about relationships between grinding tool designs and economic decisions made by individuals engaged in food processing. It will also contribute to improving interpretations of use-wear patterns on ground stone tools. The project will be completed over a two-year period with the help of community volunteers and university students who will participate in the experimental process. The project will also produce both a physical and a digital reference set for future use-wear analysis.
