Agriculture was taking root in South America almost as early as the first farmers were breaking ground in the Middle East, research indicates. Evidence that squash was being grown nearly 10,000 years ago, in what is now Peru, is reported in the journal Science. A team led by anthropologist Tom Dillehay of Vanderbilt University also uncovered remains of peanuts from 7,600 years ago and cotton dated to 5,500 years ago in the floors and hearths of sites in the Nanchoc valley of northern Peru.
     "We believe the development of agriculture by the Nanchoc people served as a catalyst for cultural and social changes that eventually led to intensified agriculture, institutionalised political power and new towns in the Andean highlands and along the coast 4,000 to 5,500 years ago," Mr Dillehay said. The earliest evidence of growing wheat, barley and legumes dates to about 10,000 to 12,000 years ago in the Middle East. "The plants we found in northern Peru did not typically grow in the wild in that area," Mr Dillehay said. "We believe they must have therefore been domesticated elsewhere first and then brought to this valley by traders or mobile horticulturists."
     Dillehay and his colleagues found wild-type peanuts, squash and cotton as well as a quinoa-like grain, manioc and other tubers and fruits in the floors and hearths of buried preceramic sites, garden plots, irrigation canals, storage structures and on hoes. "The use of these domesticated plants goes along with broader cultural changes we believe existed at that time in this area, such as people staying in one place, developing irrigation and other water management techniques, creating public ceremonials, building mounds and obtaining and saving exotic artifacts," Dillehay said. That finding correlates well with previous studies showing a trade in obsidian, a naturally occurring glass used to make knives, between the mountains and the coast 10,000 years ago, said archeobotanist Dolores Piperno of the Smithsonian Tropical Research Institute in Panama.
     "We always thought there was a gap of several thousand years before agriculture began in the New World," said archeologist Jack Rossen of Ithaca College in New York, one of the authors of the report. The new find "is bringing it into line with dates from the Old World." Researchers now know that domestication of crops occurred independently in at least 10 locations around the world, including Africa, southern India and New Guinea.

Sources: EurekAlert! (28 June 2007), Los Angeles Times, The Guardian (29 June 2007)