Overview
J2b-Z40821 is a downstream component of the J2b-M241 radiation and is particularly associated with the demographic history of the southern Balkans, the Adriatic basin and western Anatolia. Its early formation overlaps with the Neolithic spread of farming populations into southeastern Europe, where it likely became integrated into both inland agrarian communities and maritime groups using early Aegean and Adriatic sea routes. During the Bronze Age, Z40821-bearing populations participated in the cultural networks that linked the Mycenaean sphere, western Anatolia and coastal Balkan communities. The structure of downstream clades reveals localized founder events in coastal settlements, small river valleys and island microregions. Its persistence into Iron Age and classical populations underscores a stable presence within southern Balkan and Aegean demographic landscapes.