John Roney
Bureau of Land Management
Robert Hard
University of Texas at San Antonio
Ancient Corn: A Timeline
Genetic evidence suggests that corn (Zea mayes) originated in the Rio Balsas area of western Mexico, at perhaps 7200 BC. A series of recent studies indicate rapid initial dispersal through tropical settings, with evidence of maize cultivation in Panama at 5800 BC, on the Gulf coast of Mexico near Tabasco by 5100 BC, and in coastal Equador as early as 5000 BC. By 4300 BC maize was being grown in highland settings in Oaxaca, Mexico, and by 3500 BC it appears in the Tehuacan Valley of Puebla. Along the southern Pacific coast of Mexico corn is found in association with large shell midden sites as early as 2500 BC, but it does not appear in coastal sequences near Acapulco until after 1800 BC. It was present in Tamaulipas by 2400 BC, and reached the southwestern United States by about 2100 BC.
