Immigration among Neolithic people caused Mesopotamia to be genetically diverse - study

Findings show that Çayönü was a genetically diverse population because it carried mixed ancestry from the west and east sides of the Fertile Crescent - caused by immigration.

 Cranial features of the cay008 toddler. (photo credit: Altınışık et al.)
Cranial features of the cay008 toddler.
(photo credit: Altınışık et al.)

New data on people living in Mesopotamia in the Neolithic period shows how immigration caused the land to be genetically diverse, according to a recent study conducted by Turkish researchers.

The study, which was published in Science Advances on Friday, presented 13 different ancient genomes between 8500 to 7500 BCE  from Pre-Pottery Neolithic Çayönü in the Tigris river.

“The question has remained as to whether this cultural dynamism was driven by large-scale population circulation at the site, especially through connections with distant regions of the Fertile Crescent, or whether it purely reflected the local community's ingenuity,” said N. Ezgi Altınışık, first author of the study. “Our 13 ancient genomes, the largest sample produced yet from this region, allowed us to finally address this.”

“The question has remained as to whether this cultural dynamism was driven by large-scale population circulation at the site, especially through connections with distant regions of the Fertile Crescent, or whether it purely reflected the local community's ingenuity."

N. Ezgi Altınışık

Findings show that Çayönü was a genetically diverse population because it carried mixed ancestry from the west and east sides of the Fertile Crescent - caused by immigration. The cultural dynamics in Upper Mesopotamia are also likely due to its fertile lands and its interregional demographic connections.

Other findings include how communities in the area were organized along biological family lines and that the eastern gene flow to Anatolia in the Neolithic period is likely traced back to Upper Mesopotamia.

 An aerial view of date palm trees by the banks of the Euphrates in the heart of ancient Mesopotamia, near the site of Babylon in Iraq May 12, 2006. (credit: REUTERS) An aerial view of date palm trees by the banks of the Euphrates in the heart of ancient Mesopotamia, near the site of Babylon in Iraq May 12, 2006. (credit: REUTERS)

How did the researchers arrive at these conclusions?

The researchers extracted 14 people's DNA that was discovered in a burial site in Çayönü. Two of the 14 are said to be twins, which ends up being 13 different genomes.

The group also looks at 76 people who were buried together and showed that they were all related upon further analysis, which encouraged researchers to hypothesize that co-burial practices were enforced among family members in the Neolithic period.