haplogroups.info
Y-DNA Haplogroup Atlas

A · A1 · A1b · A1b1 · BT · CT · CF · F · G · G2 · G2a · G2a1 · G2a1b

Haplogroup G2a1b

G-Y12975

Macro-haplogroup
G
Parent clade
G2a1
Formed (estimate)
c. 9,500–11,000 years before present
TMRCA (estimate)
c. 5,000–6,500 years ago

Overview

G2a1b is a downstream branch of G2a1 associated with the expansion of Chalcolithic and Early Bronze Age societies across the northern Fertile Crescent, eastern Anatolia and the South Caucasus. Archaeological correlations suggest that the paternal ancestors of G2a1b carriers participated in early transregional exchange networks linking highland and lowland settlements. Compared to G2a1a, which maintained a stronger Iranian plateau focus, G2a1b displays a wider westward orientation consistent with populations that interacted with both Anatolian and Mesopotamian cultural zones.

Geographic distribution

Modern distributions peak in eastern Turkey, Armenia, northern Iraq, and western Iran. Minor traces are recorded in Syria, Georgia, and Cyprus. The pattern implies sustained presence in regions surrounding Lake Van, the Upper Tigris basin, and the Armenian Highlands—major prehistoric crossroads with deep demographic continuity.

Ancient DNA

  • Chalcolithic–Early Bronze Age samples from the Upper Euphrates/Upper Tigris corridor show haplotypes consistent with G2a1b-related ancestry.
  • Proto-Uruk and post-Uruk northern Mesopotamian individuals cluster near G2a1b-bearing groups in genome-wide analyses.
  • No unambiguous G2a1b ancient Y assignment exists yet due to limited resolution in many samples.

Phylogeny & subclades

Defined by Y12975 and related variants, G2a1b forms the sister branch of G2a1a. The lineage has several moderately deep internal sub-branches, largely concentrated within the Armenian Highlands and eastern Anatolia. Phylogenetically, G2a1b contributes to the broader mosaic of G2a diversity that characterizes early West Asian societies.

  • G2a1b* (basal)
  • G2a1b1 (Y12990-linked regional cluster)
  • Private Anatolian and Armenian microbranches

Notes & context

G2a1b encapsulates an important demographic layer of early highland–lowland interaction across eastern Anatolia and northern Mesopotamia. Its presence in regions with some of the earliest proto-urban systems highlights its relevance for understanding the paternal structure of emerging Bronze Age cultures.