Heading to the supermarket to pick up some corn flour, a couple of tomatoes or a can of beans usually doesn't conjure up the notion of 10,000 years of agricultural development in the Americas--a transition from hunter-gatherer cultures to agricultural cultures actively developing and trading new food crops. But this transition is still inadequately understood. New excavations and a growing collection of plant microfossil remains rapidly adds pieces to this puzzle.
A multidisciplinary team excavated a stone house at Waynuna, north of Arequipa on the western slope of the Andes and analyzed plant remains from three grinding stones.
Arrowroot from the Amazon. Starchy arrowroot (Maranta sp.) tubers don't grow in the Andean highlands. So the presence of tiny Arrowroot starch grains and phytoliths on the grinding stones and in associated sediments means that people were moving tubers from lowland Amazon rainforest sites east of the Andes west to the Waynuna site.
Maize from Mexico. Maize (Zea mays) cultivation also swept through the Americas in the millennia following its domestication from Teosinte, a wild ancestor from Mexico's tropical Balsas river valley, some 9000 years ago. At the Waynuna site, maize starch grains were the most common plant remains on the grinding stones. Phytoliths derived from the leaves of maize provided evidence that maize was grown at the site. The shape and grinding damage of maize particles suggests that two races of maize--one used as flour and another, popc
Contact: Dolores Piperno
Smithsonian Tropical Research Institute