It now appears that Ancient Americans took up farming twice as long ago as previously thought, and their first big crop was not the fabled corn plant, but squash. About 10,000 years ago, hunter-gatherers in what is now southern Mexico started hedging their edible bets by cultivating a baseball-size squash called Cucurbita pepo. That is at least 5,000 years before the first evidence of domesticated beans and corn -- the other two staple cultivars of Mesoamerican prehistory -- and roughly coincident with the dawn of agriculture in Mesopotamia where barley first was raised.
In the Near East and Asia, it is often assumed that hunters and gatherers made a very short transition to farmers with some estimates as brief as 500 years. The new analysis of squash seeds, stems and rinds from a cave in Oaxaca show that the change to a domesticated squash perhaps lasted some 6,000 years in the Americas.
Some of the oldest known agricultural remains (seeds and bits of plants) from Mexico were discovered in the 1960s by Kent V. Flannery of the University of Michigan in a cave named Guila Naquitz near Oaxaca. Initial dating of the material by the radiocarbon method -- which relies on the predictable decay rate of a radioactive form of carbon that plants accumulate while alive -- suggested that the find was close to 10,000 years old. That exciting but uncertain hypothesis prevailed temporarily. By the mid-1980s, researchers had developed a sophisticated technique for assessing the radiocarbon age of biological specimens, called accelerator mass spectroscopy (AMS), that could accommodate very small quantities of sample material. When that method was applied to the Oaxaca remains, it showed that they were no more than 5,000 years old and perhaps younger. AMS dating showed the new samples of squash from Oaxaca to be between 10,000 and 8,000 years old. The remains appear to be artificially evolved cousins of wild squash that had developed larger seeds and different shapes in the course of manipulation.
In the Middle East, permanent village life began even before agriculture because in some areas wild barley and wheat grew densely enough to support many people, often producing hundreds of pounds of food per acre. Villages naturally formed there before people started experimenting with domesticated crops.
In Mexico, however, we have the reverse situation. The first villages don't show up until about 4,500 to 6,500 years after the new evidence of cultivation (around 1500 B.C.). There's a long gap where people are still living like hunters and gatherers in Mesoamerica. One of the major reasons, it seems, is that the most important plant in the region was corn. It doesn't naturally form huge stands like wheat and barley. Moreover, the aboriginal wild corn plant (called teosinte) was an unappetizing thing with a tiny spike of seeds instead of the modern-day cob. Archaeologists suspect that it may have taken thousands of years for people to breed a suitably edible and prolific strain of maize.
Therefore, the process of sedentism (settling into villages) is different between the New and Old Worlds in terms of timing. The relative abundance of natural plant foods in the Old World enabled people to settle into villages earlier. It required a process of domestication in the New World before the food supply reached a point to support permanent village life. It appears to have taken thousands of years for this to happen in the New World.
The new findings show us that agriculture is not just one phenomenon that's uniform all over the world in various cultures. In fact, there were different patterns followed throughout the world. The outcomes were slightly different because the plants involved in these regions were different."