Doctoral Dissertation Improvement Grant: A Case Study in Agricultural Practice and Domestication

Washington University, Saint Louis MO

Investigators

Abstract

During the "Neolithic Revolution" - the domestication of plants and animals - a fundamental change occurred in the relationship between humans and the environment in which they lived. A central goal of this research is to gain insight into the forces which underlie this process. Under athe direction of Dr. Gayle Fritz, Natalie Mueller will conduct doctoral dissertation research. From c. 1000 BCE - 1400 CE, a suite of native seed crops known as the Eastern Agricultural Complex (EAC) was cultivated in Eastern North America (ENA). Previous studies have demonstrated that several of these crops were domesticated based on morphological changes such as seed shape, size, seed or fruit coat thickness, and texture. Two members of the EAC, sunflower (Helianthus annuus var. macrocarpus) and acorn squash (Cucurbita pepo ssp. pepo var. ovifera), are still familiar foods, but the other members of the crop complex have not been cultivated for several hundred years. These lost crops include two domesticated plants: Chenopodium berlandieri ssp. jonesianum, which is a native relative of quinoa; and a species of marshelder (Iva annua var. macrocarpa). For one important ancient crop, knotweed (Polygonum sp.), complex and variable seed morphology has so far stymied efforts to establish criteria for domestication. This case study will develop new morphometric methods to examine changes in the morphology of knotweed and determine whether or not it was domesticated. Morphological changes in domesticated plants are the result of human selection and ecosystem engineering. Past agricultural practices can be inferred from the modifications they caused in plants and animals. This study will use multivariate and spatial techniques to uncover correlations between morphological changes in knotweed and environmental, archaeological, and temporal factors. These correlations will be used to reconstruct forgotten agricultural practices. Recovering the details of agricultural economies in ENA is particularly interesting because early farmers in this region, while developing a highly productive agricultural system, did not follow the archetypal Neolithic Revolution trajectory towards institutionalized social stratification and urbanism. This project uses a case study of one important crop to gain new insights into the development of this unique agricultural economy, while enhancing understanding of a plant that was once an important crop in ENA. In an era when new seed crops are rapidly being developed, this study is a first step to assessing its potential usefulness to modern society. This research will also provide several concrete benefits to professional archaeologists and students. This project will generate a web database of integrated archaeological and botanical data from publications and collections that are currently scattered in inaccessible reports. The methods developed in the course of this project will also be used as teaching tools. Opportunities to participate in this research will be built into a new multidisciplinary course: Historical Ecology of North America. The new methods developed for using digital photography and morphometrics to study domestication will enrich Washington University's Paleoethnobotany Laboratory, where students and faculty are involved in studying the origins of agriculture around the world. This methodology will also be integrated into a course on microscopy for archaeologists. The proposed research is part of a larger movement to historicize pre-Columbian America. The dissemination of this research will be directed towards the goal of increasing public and academic awareness of ENA as a region with a long and rich pre-colonial history that is relevant to an understanding of global processes.