Transition to Maize Agriculture Along the Pacific Coast of Mexico

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

With National Science Foundation support Dr. Douglas Kennett and his colleagues will conduct two field seasons of archaeological and paleoenvironmental research on the Pacific coast of Mexico. The primary scientific aim of this work is to study the transition to maize agriculture in two different coastal settings-one in the state of Chiapas and the other in Guerrero-between 7,500 and 2,700 years ago (BP). and the impacts that the emergence of intensive agriculture had on local environments in each area. The most recent biogeographical and genetic studies indicate that maize evolved from a wild grass (teosinte) in the Balsas River Valley, which runs from the central highlands of Mexico to the Pacific Ocean. A domesticated form of maize appears to have spread out of the Balsas River Valley as early as 7,500 BP. One of the hallmarks of Middle American civilizations, maize agriculture was well established in a variety of different environments by 2,500 BP. Recent work in Middle America indicates that the processes involved in this transition were complex and spatially variable. At a minimum the sequence of events included: 1) initial domestication of maize; 2) adoption of maize by foragers living in a wide range of habitats; 3) subsequent experimentation leading to agricultural development or stability of mixed subsistence strategies; 4) ultimate emergence of more intensive agricultural strategies in certain locations; and finally 5) spread of agricultural economies via adoption or population movement/replacement. In an evolutionary sense, the initial adoption and use of key domesticates by foraging populations living in different environments was a crucial part of the ultimate development of agrarian life in Middle America. To study the process of adoption and development this multidisciplinary project employs: 1) archaeological survey and excavation of sites dating to this transitional interval, 2) off-site sediment coring, and associated geomorphological/pollen studies, to detect the initial introduction of maize into each area and to track vegetation changes and impacts to the landscape associated with intensified agriculture. The emergence of agriculture is one of the most significant transitions in the cultural evolution of our species. Its spread around the world was, and continues to be, a complex process and archaeological evidence from different parts of the world indicates that the details of this transformation varied greatly, particularly the types of domesticates adopted and the resistance of foraging populations to use them. Reconstructing the foraging strategies that were in use in a variety of habitats prior to the spread of key domesticates, like maize, will provide us with a better understanding of the primary mechanisms underlying this fundamental economic transition.