Overview
Haplogroup I3h is a rare and deeply diverging branch of the I3 lineage that appears to have formed among Upper Paleolithic populations in the highland zones bridging eastern Anatolia, the Caucasus foothills and northern Mesopotamia. Its time depth indicates survival through the climatic extremes of the Last Glacial Maximum and subsequent early Holocene transitions. I3h preserves a fragment of the early West Eurasian paternal landscape that later became heavily overlain by Neolithic farmer and Bronze Age steppe expansions.
Geographic distribution
Modern carriers of I3h are extremely uncommon. Documented examples occur in eastern Turkey, northern Iraq, western Iran and parts of Armenia and Georgia. Small clusters in diaspora populations of the eastern Mediterranean and Near Eastern origin likely reflect recent movements out of this highland core region. Its restricted and rugged geographic footprint is consistent with long-term persistence in mountainous refugia.
Ancient DNA
- Genomic studies of Upper Paleolithic and Epipaleolithic individuals from the Caucasus and northern Mesopotamia reveal highly divergent West Eurasian paternal lineages that fit the expected age and structure of I3 subbranches such as I3h.
- Pre-Pottery Neolithic samples from the northern Fertile Crescent show Y chromosome variation that includes basal I and J-related clades, within which the deep I3 complex is positioned.
- Chalcolithic and Bronze Age individuals from the Armenian Highlands and Zagros foothills often carry mixed ancestries combining incoming farmer and steppe components with older highland substrata, providing a plausible context for the survival of I3h.
Phylogeny & subclades
Within haplogroup I3, I3h forms a sister line to other very old subbranches such as I3d, I3e and I3f. The defining SNP Y18670 and associated markers like Y18672 delineate a tight cluster with minimal downstream radiation. This pattern is characteristic of lineages that remained confined to small, geographically isolated populations over long time periods.
- I3-Y18672
- Basal I3h* highland Near Eastern lineages
Notes & context
I3h is important for reconstructing the deep-time demographic structure of highland West Asia. Although numerically rare, it helps anchor the early diversification of the I3 lineage and illustrates how rugged landscapes can preserve ancient paternal diversity that is largely invisible in more heavily admixed lowland populations.
References & external links