A Florida State University anthropologist has discovered new evidence that suggests that ancient farmers in Mexico cultivated an early form of maize, the forerunner of modern corn, about 7,300 years ago, almost 1,200 years earlier than previously thought.
     Professor Mary Pohl conducted an analysis of sediments in the Gulf Coast of Tabasco, Mexico, and concluded that people were planting crops in the 'New World' of the Americas around 5,300 BCE. "This research expands our knowledge on the transition to agriculture in Mesoamerica," Pohl said. "These are significant new findings that fill out knowledge of the patterns of early farming. It expands on research that demonstrates that maize spread quickly from its hearth of domestication in southwest Mexico to southeast Mexico and other tropical areas in the New World including Panama and South America."
     The shift from foraging to the cultivation of food was a significant change in lifestyle for these ancient people and laid the foundation for the later development of complex society and the rise of the Olmec civilization, Pohl said. The Olmecs predated the better known Mayans by about 1,000 years. "Our study shows that these early maize cultivators located themselves on barrier islands between the sea and coastal lagoons, where they could continue to fish as well as grow crops," she said.
     During her field work in Tabasco seven years ago, Pohl found traces of pollen from primitive maize and evidence of forest clearing dating to about 5,100 BCE. Pohl's current study analyzed phytoliths, the silica structure of the plant, which puts the date of the introduction of maize in southeastern Mexico 200 years earlier than her pollen data indicated. It also shows that maize was present at least a couple hundred years before the major onset of forest clearing. Traces of charcoal found in the soil in 2000 indicated the ancient farmers used fire to clear the fields on beach ridges to grow the crops.
     The phytolith study also was able to confirm that the plant was, in fact, domesticated maize as opposed to a form of its ancestor, a wild grass known as teosinte. Primitive maize was probably domesticated from teosinte and transported to the Gulf Coast lowlands where it was cultivated, according to Pohl. The discovery of cultivated maize in Tabasco, a tropical lowland area of Mexico, challenges previously held ideas that Mesoamerican farming originated in the semi-arid highlands of Mexico and shows an early exchange of food plants.

Sources: EurekAlert! (9 April 2007), Yahoo! News (10 April 2007)