Evrim Yazgin
Cosmos science journalist
DNA from 131 ancient individuals throughout the Caucasus region between Europe and Asia has been analysed, pointing to a split into two populations – one group became farmers, while the others continued living a hunter-gatherer lifestyle.
The region is known as one of the earliest places people practiced animal husbandry. The new study adds insight into how this developed.
The study, published in Nature, spans nearly 6,000 years of genetic data in the region.
The Caucasus mountains are on the border between Europe and Asia. They stretch between the Black Sea to the west and the Caspian Sea to the east. The mountain range spreads between 6 countries: Georgia, Russia, Azerbaijan, Armenia, Turkey and Iran.
People made it to the Caucasus mountains more than 8,000 years ago. During the Mesolithic, or Middle Stone Age – a period which ended around the year 6000 BCE.
“The oldest individuals in this study are from Satanaj cave in Russia (6221–6082 BCE), and from the early Neolithic site of Arukhlo in Georgia (5885–5476 BCE),” the authors write.
The researchers also took samples from the subsequent Eneolithic (4th–5th millennia BCE) – a period which in Europe is referred to as the Copper Age. The latest samples are from the Late Bronze Age, a little more than 3,000 years ago.
All up, the samples came from 38 sites across the Caucasus region.
The researchers noted a strong genetic difference between populations north and south of the Caucasus mountains.
In the north, the genetic data showed Eastern hunter-gatherer ancestry. In the south, there was a distinct Eastern hunter-gatherer ancestry with East Anatolian farmer populations DNA mixed in increasingly over time.
It’s possible that people from Anatolia, now Turkey, introduced farming techniques to the Caucasian groups. This southern Caucasian population would become among the first people in the world to develop animal husbandry.
During the Eneolithic, they noted some of the earliest evidence of West Eurasian steppe cultures and pastoralist societies emerging. They suggest this is a result of “heightened interaction between the mountain and steppe regions, facilitated by technological developments”.
They found long-term genetic stability through the Early and Middle Bronze Age.
In the Late Bronze Age, there was a new influx of genetic diversity coinciding with the decline of the steppe cultures which were increasingly absorbed into the communities living in the highlands.
