Doctoral Dissertation Improvement Grant: Modern Agrobiodiversity Issues and Their Relevance to the Study of Prehistoric Agriculture

Washington University, Saint Louis MO

Investigators

Abstract

Modern agricultural biodiversity is the product of thousands of years of farmer experimentation and informal breeding. Archaeology is uniquely positioned to investigate questions surrounding the initial domestication of plants and the subsequent creation and maintenance of crop biodiversity. Currently, however, a lack of suitable methods prevents archaeologists from successfully exploring issues of biodiversity via the archaeological record. Under the supervision of Dr. Patty Jo Watson, Angela Gordon will combine information from agronomy with fieldwork in Mexico to test one means of identifying biodiversity in the archaeological record. The project focuses on Chenopodium berlandieri, a high-protein crop domesticated prehistorically in Mexico and eastern North America. It is a domesticate today, however, only in Mexico. The eastern North American domesticated chenopod is known only from the archaeological record; by the time of European contact, it was no longer grown. Various Chenopodium species have been domesticated or heavily exploited in many regions around the world, primarily for the nutritious seeds. In the central Mexican highlands, huazontles and quelites de trigo, both forms of domesticated C. berlandieri, are grown for the immature flowering heads and the greens, respectively. Farmers maintain distinct varieties for each of these use-types and, in west-central Mexico, also maintain a red-seeded variety that is used as a grain. Ms. Gordon will study how Mexican farmers maintain these distinct varieties, and will gather multiple samples of each for comparison. Through microscopic examination of differences in seed morphology, she will create a key to the different use-varieties. While it has always been assumed that the eastern North American chenopod was grown for its high-protein seeds, this key will allow archaeologists to identify other uses from the archaeologically recovered seeds. The Mexican chenopods offer an exciting opportunity to examine modern biodiversity of this crop species while also providing an excellent analog for understanding the extinct eastern North American crop. In addition, this research will provide archaeologists with a new method for examining crop biodiversity via the archaeological record. This research will also gather valuable information about chenopod cultivation and biodiversity before it is too late. Subsistence farmers around the world are the primary guardians of agricultural biodiversity. As farming becomes standardized and mechanized in the developing world, agricultural biodiversity is lost. Minor crops, such as the Mexican chenopods, are particularly vulnerable because global economic priorities create incentives for farmers to give up traditional subsistence crops in favor of cash crops for market or export. In most cases, traditional knowledge and biodiversity are lost. This research will ensure that some of this knowledge and biodiversity is recorded.