The Role of the Middle Cauca River Valley, Colombia, in the Early Domestication and Dispersal of New World Crops

Temple University, Philadelphia PA

Investigators

Abstract

With the support of the National Science Foundation, Drs. Anthony Ranere, Ruth Dickau and an international team of researchers will conduct archaeological and paleoecological fieldwork over a two year period in the Middle Cauca River Valley of Colombia. The project brings together researchers and students from institutions in the United States, Great Britain and Colombia with expertise in archaeology, paleoethnobotany, paleoecology and geology. The research seeks to document the initial appearance of cultivation in the subsistence strategies of populations in the Middle Cauca River Valley and to identify the plant species that were either domesticated in this region or imported from elsewhere in South America or Central America. Research to date has demonstrated that species from Mexico to Brazil came under domestication early in the Holocene (ca. 9,000-10,000 years ago) and became widely dispersed over the next two or three millennia. A number of crops appear to have been domesticated in the seasonal tropical forests of northern South America, including arrowroot, sweet potato, leren, achira and possibly cocoyam, as well as a variety of squash. The Middle Cauca River Valley of Colombia is an especially promising region for examining the early cultivation, domestication and dispersal of plant species because of the numerous sites identified here with early Holocene deposits containing both microfossil remains and artifactual evidence for plant cultivation. The project will focus on the recovery of plant remains from tools and sediments in archaeological sites already identified and tested by project personnel. Additionally, a site survey and testing program will be carried out aimed at locating sites that would extend the occupational history of the region back into the Late Pleistocene. Vegetational history will be established through an analysis of pollen and phytolith sequences paying particular attention to disturbance indicators reflecting cultivation activities. The identification of specific taxa utilized will rely primarily on analysis of starch grains and phytoliths, and secondarily on plant macrofossils and pollen. In order to confidently distinguish starch grains and phytoliths produced by domesticated species from those produced by their wild progenitors and relatives, botanical collecting of both domesticated and wild taxa will be undertaken to establish comprehensive reference collections for the study region. The domestication of plants - and the subsequent development of agricultural economies - constitutes one of the most transformative episodes in human history. The intellectual merit of the project is the contribution it will make to our understanding of when, where and under what circumstances the critical change from gathering to cultivating plants first came about in tropical America. The broader impact of the project includes providing students from several academic institutions with the opportunity to participate in both field and laboratory aspects of the research, thereby contributing to their training as future professionals. In addition, the comparative reference collections of starch grains and phytoliths will be made available on the web for use by other researchers studying the ancient use of plants in the American tropics. A GIS database with project generated data will also be put on the web.