Trialeti–Vanadzor Culture and Its Genetic Legacy in the South Caucasus
The possible steppe connection and Indo-European affiliation of the Trialeti-Vanadzor culture have been discussed for a long time. However, its partial presence in regions that later became known as Iberia and Caucasian Albania made this interpretation difficult to accept.
Today, ancient DNA allows us to better understand past population shifts and helps resolve these apparent contradictions.
Y-DNA Patterns in Eastern Georgia
The first Y-DNA chart (based on Skourtanioti et al. 2024) excludes one sample from western Georgia.
During the Late Bronze Age–Early Iron Age (1500–800 BCE)—known in eastern Georgia as the Lchashen-Tsitelgori culture—the Y-DNA distribution closely resembles that of Armenia:
- A predominance of R1b and I2, lineages that expanded during the Middle Bronze Age with the Trialeti–Vanadzor horizon
- Two J2 samples from the Bazaleti site (north of Mtskheta), near the foothills of the Greater Caucasus
One of these J2 individuals shows low steppe ancestry, indicating the northern boundary of Trialeti–Vanadzor influence, consistent with the region’s lowland–highland geographic division.
A single G2a1 sample suggests that central Georgian Kura–Araxes-derived populations may have had a different Y-DNA structure compared to Kakhetian groups, which were predominantly J1.
Iron Age Transformations
In the Iron Age II (800–600 BCE), data are limited, with only one G2a1 sample available.
The Early Antiquity period (600–300 BCE)—coinciding with the rise of the Achaemenid Empire—shows a major shift:
- Appearance of R1a in both Armenia and Georgia
- Increased importance of G2a1 and J2 lineages (likely subclades of CTS900)
Unlike Armenia, which experienced a southward genetic shift, eastern Georgia likely underwent a different directional change, though current qpAdm models lack sufficient resolution to define it precisely.
The Bragdzor Family: Evidence of Migration
A key insight comes from a familial burial at Bragdzor.
Three individuals were closely related:
- The father and his brother shared Y-DNA (J2) and mtDNA (K1a4c)
- The father displayed autosomal DNA very different from local Lchashen populations
He had:
- High CHG (Caucasus Hunter-Gatherer ancestry)
- Virtually no steppe ancestry
- A profile similar to modern West Georgians
This indicates that he was a migrant, arriving in the region around 800 BCE.
This date coincides with the proposed linguistic separation of Kartvelian languages, including the divergence of Georgian and Zan, which typically occurs alongside geographic expansion.
Further evidence of migration:
- His son’s mother (likely his wife, buried in the same grave) was an Etiuni/Lchashen woman, suggesting incoming males without accompanying women
Despite this, the Bragdzor lineage did not leave a lasting genetic impact in northern Lori, as later samples show continuity with earlier populations.
Formation of Iberia and Kartvelian Expansion
In contrast, related groups did leave a strong impact in eastern Georgia, contributing to the formation of Proto-Iberia, later known as Iberia in the Hellenistic period.
Additional supporting samples:
- A G2a1 individual from Keti (~650 BCE)
- A Hellenistic-era individual from Samsun, likely linked to Zan populations
These individuals share:
- High CHG ancestry
- A clear distinction from Caucasian Albanian-related samples, which show more Zagros Neolithic ancestry and lower CHG
Conclusion
The steppe-derived populations that entered the South Caucasus around 2500 BCE (Trialeti–Vanadzor horizon) had a long-lasting genetic impact, visible until the Iron Age.
However, during the Iron Age:
- Mountain populations expanded into lowlands, contributing to the formation of Iberia and Caucasian Albania
- In historic Armenia, state formation under Urartu and the Orontid dynasty led to different genetic shifts
- The Achaemenid Empire likely also influenced population structure across the region
Due to the limited dataset, these interpretations remain provisional, and further ancient DNA evidence will be necessary for definitive conclusions.
