Paleogeneticists have analyzed the genome of a member of the Darkveti-Meshokov culture, who lived in the North Caucasus between 5000 and 4800 BC. The scientists determined this individual's origins and also discovered that the region's first farmers and herders contributed genetically to the population of the Khvalynsk culture, which existed in the steppes further north. The researchers hypothesized that not only cultural ties but also marital unions may have contributed to the spread of agriculture in the Volga region. They write about this in a paper published in the journal iScience.
At the beginning of the 5th millennium BC, agriculture reached the North Caucasus. Relics of the so-called Darkveti-Meshokov culture of the Eneolithic period, which existed from approximately 5000 to 3200 BC, have survived from the region's first farmers and livestock breeders. Their economy was based primarily on the cultivation of grain crops (wheat and oats) and the breeding of pigs and cattle. Hunting also played a significant role.
The only burial site of this culture, called the Nalchik burial site, was excavated by archaeologists in Nalchik in 1929 on the grounds of what is now the city hospital. It contained the remains of over a hundred people who lived at the beginning of the 5th millennium BC. The Darkveti-Meshokov culture buried their dead on their sides or backs, with their legs bent. The deceased were sprinkled with red ochre and accompanied by various artifacts. In particular, in one of the burials at this site, researchers unearthed a copper ring, one of the oldest metal artifacts in the region.
Now, scientists from Germany and Russia, led by Egor Prokhortchouk from the Russian Academy of Sciences' Center for Biotechnology, have presented the results of a genetic analysis of the individual from the Nalchik burial ground. The researchers isolated ancient DNA from the wisdom tooth of an adult male who lived between 40 and 60 years. Geneticists confirmed that the remains belonged to a male and determined that he belonged to the mitochondrial haplogroup T2c1a1 and the Y-chromosomal haplogroup R1b1.
In a plot constructed using principal component analysis, this man's genome was located next to the genomes of two individuals from the Eneolithic period in the Ciscaucasian steppe region, whose remains were found at the Progress-2 and Vonyuchka-1 sites, who lived in the early and second half of the 5th millennium BC, respectively. Furthermore, the genome of a person who lived around the same time as the Nalchik individual was also located nearby. His remains were found at the Khvalynsky-II burial site, located on the right bank of the Volga in the Saratov region, a considerable distance from the Caucasus Mountains.
Further analysis revealed that the Nalchik burial ground man's ancestry could be modeled on three ancestral populations: early farmers of Western Asia, Caucasian hunter-gatherers (or Neolithic inhabitants of Iran), and European hunter-gatherers. Moreover, the large contribution of the latter component significantly differentiated this man's genome from another previously published genome, belonging to a Darkveti-Meshokov culture representative whose remains were found in Uznakovo Cave. This is likely due to the fact that the population of the mountainous region in which this site is located had, as expected, less contact with the steppe population than the inhabitants of the border zone. Furthermore, according to the researchers, contrary to expectations, the Nalchik burial ground man was genetically closer to people from Northern Mesopotamia and the Zagros Mountains, who lived there in the 8th–7th millennia BC, than to his neighbors from the South Caucasus, who lived in this region in the 6th millennium BC.
The researchers also noted that as early as the beginning of the 5th millennium BC, the first farmers and livestock breeders of the North Caucasus interbred with the population of the more northern steppes—representatives of the Khvalynsk archaeological culture, whose available genomes are quite heterogeneous. Moreover, analysis of common linkage blocks in the genomes of the individual from Nalchik and the individual from the Khvalynsk-II burial ground revealed that their chromosomes contain long, identical regions, indicating their distant relationship. The researchers hypothesized that the intensity of intermarriage between these two populations was low. However, it is possible that not only cultural contacts but also marriage contributed to the spread of livestock farming in the Volga region.
This isn't the first time N+1 has reported on research into ancient populations that inhabited the Caucasus. For example, DNA analysis of the Koban culture, which existed in the Late Bronze Age, revealed biological links between these people and some modern populations.
