Maize was Domesticated in the Lowlands of Mexico 8,700 Years Ago

Maize was domesticated from its wild weed ancestor, teosinte, some 8,700 years ago, according to two papers published this week by PNAS. The scientists place maize domestication in the lowland areas of southwestern Mexico about 1,500 years earlier than previously reported.

The scientists found maize remains, as well as ancient stone tools used to grind and mill the plants, in an archaeological site near the Balsas Valley. The region is home to the Balsas teosinte, a large wild grass that molecular biologists identified as the ancestor of maize. The findings confirmed the hypothesis that maize was domesticated in lowland areas, as opposed to being domesticated in the arid highlands, which many researchers previously believed

Scientists have been interested in the evolutionary history of domesticated crops. But it took them until 2005 to include the Balsas River Valley in their search for the roots of maize domestication. In 2005, the researchers found evidences, in the form of pollen and charcoal in lake sediments, that forests were being cut down and burned in the Central Balsas River Valley to create agricultural plots by 7000 years ago.

Read the complete article at http://www.temple.edu/newsroom/2008_2009/03/stories/balsas_teosinte.htm The papers published by PNAS are available at http://dx.doi.org/10.1073/pnas.0812525106 and http://dx.doi.org/10.1073/pnas.0812590106