© The Archaeology News NetworkThe new study analysed the genomes of early farmers from Iran's Zagros mountains.
Conducting the first large-scale, genome-wide analyses of ancient human remains from the Near East, an international team led by Harvard Medical School has illuminated the genetic identities and population dynamics of the world's first farmers.
The study reveals three genetically distinct farming populations living in the Near East at the dawn of agriculture 12,000 to 8,000 years ago: two newly described groups in Iran and the Levant and a previously reported group in Anatolia, in what is now Turkey.The findings,
published in Nature, also suggest that agriculture spread in the Near East at least in part because existing groups invented or adopted farming technologies, rather than because one population replaced another.
"Some of the earliest farming was practiced in the Levant, including Israel and Jordan, and in the Zagros mountains of Iran--two edges of the Fertile Crescent," said Ron Pinhasi, associate professor of archaeology at University College Dublin and co-senior author of the study.
"We wanted to find out whether these early farmers were genetically similar to one another or to the hunter-gatherers who lived there before so we could learn more about how the world's first agricultural transition occurred."
The team's analyses alter what is known about the genetic heritage of present-day people in western Eurasia. They now appear to have descended from four major groups: hunter-gatherers in what is now western Europe, hunter-gatherers in eastern Europe and the Russian steppe, the Iran farming group and the Levant farming group.
"We found that the relatively homogeneous population seen across western Eurasia today, including Europe and the Near East, used to be a highly substructured collection of people who were as different from one another as present-day Europeans are from East Asians," said David Reich, professor of genetics at Harvard Medical School and co-senior author of the study.
"Near East populations mixed with one another over time and migrated into surrounding regions to mix with the people living there until those initially quite diverse groups became genetically very similar," added Iosif Lazaridis, HMS research fellow in genetics and first author of the study.