Overview
Haplogroup R-Z2109 is a major downstream branch of R-Z2106 and represents one of the most widespread Bronze and Iron Age paternal lineages across the Balkans, the Caucasus and parts of Anatolia. Its formation coincides with the later phases of the steppe related expansions into southeastern Europe. Z2109 appears prominently in ancient Y DNA datasets from the Balkans during the Bronze Age, suggesting it was carried by groups involved in the formation of Thracian, Illyrian and early proto Greek populations. Z2109 is a key lineage for understanding the demographic transformations of Bronze and Iron Age southeastern Europe. Its subclades appear among populations involved in the spread of Indo European languages into the southern Balkans and the later incorporation of steppe derived ancestry into Mediterranean societies. Archaeogenetic results indicate that Z2109 lineages continued to persist into classical and medieval times, forming part of the paternal ancestry of many Balkan and Anatolian populations. Its wide geographic span also reflects later historical processes, including the mobility of classical Greek, Hellenistic and Roman era populations and medieval migrations across the Balkans and Caucasus. Z2109’s internal diversity demonstrates long term regional continuity in southeastern Europe.