Overview
J1-FGC8621 is a downstream lineage within the highland-oriented J1-Z1828 complex, formed among upland agro-pastoral societies in the South Caucasus, eastern Anatolia and the northern Zagros. Its early development is linked to highland cultural systems characterized by fortified upland villages, early metallurgy and obsidian distribution networks. These environments promoted demographic stability, leading to the formation of microbranch clusters that persisted for millennia. During the Bronze and Iron Ages, FGC8621-bearing populations remained concentrated in mountainous zones where ecological isolation reinforced endogamous social structures. The clade's phylogeny reflects persistent continuity across upland communities, with downstream diversification corresponding to localized founder effects in Armenian and Georgian highland groups.