افزایش کشت برنج آفریقایی و استفاده اقتصادی از گیاهان در بالا نیجر میانه دلتا (مالی)
Abstract: This research examines the rise of African rice farming and the economic use of plants at the Dia archaeological mound complex, in the upper Middle Niger Delta (MND), during the Late Stone Age to Iron Age transition. Although the Middle Niger floodplain has long been considered a primary center of African rice (Oryza glaberrima ) domestication, the place and timing of genetic transformation remain unknown. At Dia, numerous African rice grains were recovered from the earliest occupations (800-500 BC), but because naked grains of wild and domesticated taxa are visually indistinct, specific determination was difficult. This project focused on finding methods of distinguishing wild and domesticated rice grains in order to address questions about cultivation, domestication, and the development of farming. In addition, this research examined change through time in human and plant interaction at Dia to understand subsistence and trade activities practiced throughout the site\'s occupation, roughly 800 BC to AD 1600. Determination of African rice to species was attempted through study of DNA and lipids recovered from the ancient grains. The highly charred condition of the caryopses, however, prevented successful extraction of viable material. Morphometrical analysis of grains using ratios of length, width, and thickness shows that rice from the earliest levels at Dia more closely resembles the modern domesticate than the modern wild species, suggesting that rice was domesticated prior to 800 BC and that it was introduced from elsewhere. The ubiquity of rice remains throughout Dia\'s occupation implies that rice farming was an important activity. Other highlights include a considerable quantity of cotton seeds (and spindle whorls) dating to the thirteenth century AD, which probably indicates the manufacture of string and cloth for trade, and the recovery of four wheat grains, dating to the tenth century, that likely signifies contact or commerce with sources external to West Africa. The results of this project provide fundamental information on the rise of farming in the MND, and on subsistence and trade activities in a region that eventually became the breadbasket of three major West African empires.