LOS ANGELES - A rich trove of artifacts and plant remains excavated from southwestern Iran suggests that ancient humans' transition from hunting and gathering to farming occurred throughout the Fertile Crescent at roughly the same time.
The excavation also revealed this crucial change - which helped the region earn its reputation as the cradle of civilization - happened gradually over thousands of years, not in a few generations or centuries as previously thought, according to a study published this month in the journal Science.
The findings from the excavation in the foothills of the Zagros Mountains represent a paradigm shift in scholars' understanding of agriculture's origins, and the villages, towns and civilizations that emerged as a result, experts said.
For decades, archaeologists believed agriculture took root in a part of the Fertile Crescent called the Levant, which includes present-day Israel, Lebanon and Jordan as well as parts of Syria, Iraq, Saudi Arabia and other countries. From there, it was thought to have spread eastward to present-day Iran.
"The eastern Fertile Crescent has been treated as backwater," said Melinda Zeder, a senior scientist at the Smithsonian Institution's Program in Human Ecology and Archaeobiology, who was not involved in the study. Now, the understanding that people in the Zagros grew and ground cereal grains as early as their counterparts in the Levant has "democratized this situation where everyone in the region was involved," she said.
Excavations in the western Fertile Crescent yielded evidence of plant and animal domestication dating to about 11,500 years ago, while digs in the eastern Fertile Crescent found evidence of domestication dating to only about 9,500 years ago. After the Iranian Revolution in 1979, however, Western archaeologists were unable to analyze sites in the east with the same modern recovery and dating techniques used to study those to the west.
Improved diplomatic relations between Iran and the West enabled archaeologists from the University of Tuebingen in Germany to visit the 12,000-year-old Chogha Golan site in 2009 and 2010, which they excavated with the Iranian Center for Archaeological Research. Recent genetic analysis of modern barley and animals such as sheep, pigs and goats in the eastern Fertile Crescent suggested that domestication could have begun earlier than 9,500 years ago.