Complex interaction over Caucasian range.

Complex interaction over the Caucasian range

We now have sufficient DNA from both the south and north of the Caucasus to outline the migratory events that shaped the pre-Bronze Age history of the Caucasian range. Here is a summary of these events.

Skipping the Paleolithic and Mesolithic periods, the key events are as follows:

Around 5500–5000 BC, farmers from the Kura-Araxes basin, almost certainly related to the Shulaveri culture, crossed the Caucasus and moved north. Although still contested by some, I have little doubt that zoological data will support the idea that pastoralism appeared in Eastern Europe due to this event. It spread rapidly north toward the Volga and slightly later toward Ukraine. These are the earliest kurganic cultures in Eastern Europe that can be linked to Indo-European populations.

However, the two most frequent haplotypes associated with pastoralism in Eastern Europe are R1b-V1636 and I2-L699, of local origin (EHG and UHG). Occasionally, J2 and J1 are observed. Notably, J2b2b from Eneolithic Moldova belongs to the same branch as Shulaveri Y-DNA from Mentesh Tepe in Azerbaijan. The J2b2a1-L283 haplotype, which later expanded with Yamnaya, might also trace back to Shulaveri. The lack of a similar change in Y-DNA, despite important autosomal shifts in Eastern Europe, is beyond the scope of this summary.

Around 4300 BC, a migration occurred from north to south. Little was known about this movement before ancient DNA evidence, but the appearance of R1b-V1636 in the south, alongside kurganic burials mixed with local jar burials, indicates that northern pastoralist groups ventured south. Their migration appears to have been limited in scale and peaceful, integrating into the so-called Chaff-Faced Ware groups present across the Highlands and South Caucasus. Steppe ancestry in Areni during the Chalcolithic period is strong evidence of this migration.

Around 3900–3800 BC, a new group moved north, likely via Daghestan, playing a role in the formation of the Maykop culture. The suggestion of a Daghestan route comes from the absence in ancient Georgia of haplotypes found in Maykop, including L2, T1a3, and J2-P81. A mass migration of Chaff-Faced Ware people via Georgia would have caused significant dilution of CHG ancestry, which is not observed, particularly in western Georgia. Maykop was complex, with contributions from Central Asia introducing haplogroup Q1. Although Maykop likely influenced Yamnaya culturally, it is not directly ancestral. Maykop Novosvobodnaya individuals had G2a2a, possibly resulting from a distinct migration via the central Caucasus, though data are still insufficient for firm conclusions.

Around 3600 BC, another migration occurred from south to north. These were Kura-Araxes culture people associated with haplotype J1-Z1842, likely moving via central Caucasus regions such as modern Mtskheta-Mtianeti or Kakheti. This event likely disrupted Maykop interests. The widespread presence of J1-Z1842 in the North Caucasus strongly associates it with Nakh-Daghestani speakers. Meanwhile, near the Azov Sea, a Proto-Yamnaya group associated with R1b-Z2103 was preparing to expand around 3500 BC. This group did not move south immediately, only after 2500 BC, later creating an offshoot in the North Caucasus known as the North Caucasian or Kubano-Tersk culture.

The map illustrates the two-way interactions between north and south over the eastern passes. The genetic history of the western passes in the Caucasus is different: it was more isolated and had less impact.