the 10 historically recognized independent centers of plant domestication
worldwide, five were in the Americas.
Three of these occurred in South America, where chile peppers,
squash, beans, yucca, yams and white and sweet potatoes were grown.
North Americas contributions included squash, maize (corn)
and beans the trifecta of New World foods as well
as other species such as chile peppers and sunflowers, the seeds
of which were consumed.
Until the last few decades, some researchers thought that North
American agriculture developed in Mexico approximately 5,000 years
ago, whereas wheat and barley were domesticated in the Near East
around 10,000 years ago. Recent discoveries, however, have dramatically
changed the North American dates while identifying new regions where
early domestication took place.
The transition from nomadic hunting-and-foraging cultures to
settled societies occurred in different places around the world
at different times, but researchers now agree that New World agriculture
started 10,000 years ago. Dolores Piperno of the Smithsonian Institution
says that agriculture began in southwest Mexico.
Around 8,000 B.C., the cold, arid climate became warmer and
wetter as atmospheric carbon dioxide levels rose. In Mesoamerica,
lowlands and tropical forests expanded, lakes filled with water,
and new plant and animal species replaced old ones. People planted
on these lake shores.
In 1997, Smithsonian archaeologist Bruce Smith dated the seeds
of a domesticated pepo (pumpkin) squash found in a cave in Oaxaca,
Mexico, to nearly 10,000 B.C., which to date is North Americas
oldest known domesticated plant.
Phytoliths fossilized mineral particles left by plants
from squash and arrow root indicate that these plants were
being grown in Panama 9,000 years ago.
Maize was one of the New Worlds earliest crops, as well
as one of its most important. A domesticated form of the wild grass
teosinte maize is rich in carbohydrates. Its easy to store
and can be ground into flour to make different foods.
Maize remained in dry caves in the semi-arid highland dating
to 5,000 years ago. They assumed that was the beginning of maize
or corn domestication. In fact, farmers were planting maize earlier
elsewhere. Mary Pohl and Kevin Pope discovered evidence that farmers
cleared forests, most likely for fields, 7,000 years ago.