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I2-Y16419
I2a1d (Y16419) is a southeastern and central European oriented branch of the I2a1 radiation, representing a lineage that persisted among late Mesolithic and early Neolithic populations of the Carpathian–Balkan arc. While less common than I2a1a or I2a1b, this branch retains archaeological relevance due to its deep antiquity and connections to local forager–farmer transitional groups.
Modern concentrations occur in Romania, Moldova, western Ukraine, and parts of Bulgaria and Serbia. Lower frequencies appear across Slovakia, Hungary and the northern Balkans. Its geographic footprint aligns with prehistoric networks around the lower Danube and Carpathian basin.
I2a1d is positioned within the broader I2a1 cluster alongside I2a1a, I2a1b and I2a1c. SNPs such as Y16419 define a stable lineage whose downstream diversification remains limited compared to explosive expansions like I2a1b.
Although less common today, I2a1d adds depth to the reconstruction of southeastern European population history and captures a non-expanded Mesolithic substrate lineage.