Under the direction of Dr. Lovis, Ms Maria Raviele will examine the process by which early maize (corn) agriculture was adopted in the eastern United States. A study area within eastern North America, the Saginaw River valley of Michigan, will be used to specifically address the problem of early use of maize (prior to AD 1000) and how this cultigen was incorporated into an already existing hunter-gatherer subsistence system. It is known from visible archaeological remains, such as cobs, that maize was grown after AD 1000. However, evidence suggests that maize and other cultivated plants were increasingly used by hunter-gatherers before this time in what is called a mobile low-level food production economy.
A relatively new methodological technique, phytolith analysis, is adopted to examine evidence for plant use. Phytoliths are microscopic deposits of silica which occur with varying frequency in every plant part. Phytoliths can be diagnostic of particular plants and are used to identify species from archaeological contexts where larger, visible plant remains are not preserved. This study extracts phytoliths from charred food remains adhering to ceramic sherd interiors. This will allow for the direct identification of plant foods being cooked in a pot. It is expected that one of the plants identified will be maize. The charred food remains to be examined are taken from ceramic sherds, dating both before and after AD 1000. This time span covers the Middle Woodland (200 BC-AD 500) and Late Woodland (AD 600-AD 1400) periods.
In addition to examining archaeological charred food remains, systematic experimental food residues, specifically using maize, were created to determine if quantifying phytoliths found in a residue is possible. This is important because current analysis simply records presence/absence. If quantification is possible, this would allow researchers to address issues such as how much of a plant was used, how the plant was processed prior to cooking and how important this plant food was in a prehistoric diet.
This project demonstrates the importance of interdisciplinary and experimental work within archaeology since it draws on disciplines in the life and environmental sciences. Human responses to the introduction and adoption of a new food source are also addressed and are pertinent to parallel issues of contemporary subsistence change. The experimental method applied here has the potential to be applied to other economically based plant utilization studies and thus has a geographical range extending beyond eastern North America. The use of museum collections also raises several methodological issues in regards to long-term curation and processing of residues. These are pertinent to other researchers as well as institutional administrators in their decisions about how to care for these finite resources. Finally, this project provides comprehensive experience in phytolith analysis for a graduate student researcher who can then train future students in this method.