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The oldest J2b ever discovered is from 10,000 years ago in Kotias Cave, Georgia. He was 100% CHG. So these J2b lineages from Iran represent a migration out of the Caucasus into Iran and beyond. There is no connection between these J2b groups in Europe and Iran, except to say that they descend from a common core group of ancestors from the Caucasus. Of course, they are on separate branches that split from one another over 10000 years ago. The European branch, J2b L283, likely forming somewhere on the steppe.