Overview
J1-ZS603 is a downstream branch of J1-L147.1, representing one of the Arabian-rooted expansions developed during the late Neolithic and early Bronze Age. The ancestral populations of this lineage were tied to pastoral systems across the northern Arabian plateau, making use of seasonal water sources, desert wells and early caravan paths that connected the Arabian interior to the Levant and Mesopotamia. By the Bronze and Iron Ages, ZS603-bearing groups became involved in the rise of North Arabian tribal confederations and trade networks associated with the desert frontier. Downstream phylogenetic segmentation suggests repeated founder events linked to regionally anchored clans in the Hejaz, Najd and southern Jordan, some of which continued into the early Islamic era.