Overview
J1-Y6521 is a downstream branch of the Arabian-centered J1-P58 expansion and likely originated among pastoralist communities spread across the northern and central Arabian Peninsula during the early Bronze Age. These ancestral groups lived around wells, seasonal wadis and oasis-linked corridors that supported short-range pastoral mobility. Their mobility networks connected the Hejaz, southern Jordan and the northern desert belt, shaping early demographic structures associated with North Arabian tribal formation. During the Bronze and Iron Ages, Y6521-bearing populations participated in the growth of tribal confederations occupying the Hejaz and Wadi Sirhan. Downstream patterns reveal several founder-driven expansions tied to clan-based structures. In the early Islamic period, Y6521 lineages expanded eastward into Iraq and the Gulf region, where new microbranches formed through localized demographic growth.