R1b

Paternal Ancient Ancestry Haplogroup R1b first arrived first arrived in Europe from West Asia during the Upper Paleolithic period (35,000-40,000 years ago) at the beginning of the Aurignacian culture. This culture is one of the first within Europe to leave cave art, and their stone tools were more refined than previous periods. The Périgordian culture is also thought by some to have existed at this time.

As the last ice age began, it became necessary to move down to below the tree line to hunt game. At its peak, the ice shelf within Europe extended down as far as southern Ireland, the middle of England and across northern Germany. Scandinavia was entirely covered. The sea ice pack extended as far as northern Spain, and tundra covered much of continental Europe. The tree line at the height of the ice age extended as far south as southern France, northern Italy, the northern Balkans and across the Black Sea.

People with Haplogroup R1 Y-chromosomes retreated to below these regions where they established themselves. As the ice age ended and the fauna and flora were able to move northward again, people in R1b also migrated north. Haplogroup R1 appears in about 50% of the total European population whereas R1b remains by far the most common haplogroup in western Europe (Spain, Portugal, France, UK and Ireland). R1b3, one of the most successful clades, has its origins about 11,800 years ago. Within the British Isles, a genetic pattern called the Atlantic Modal Haplotype (AMH) features greatly among the Irish and Welsh. Some researchers consider this haplotype to be representative of the early Celtic migrations. Haplogroup R1b is prevalent within South America because of the influx of Iberian Y chromosomes to the continent over the last 500 years.