The Western Atlantic Modal Haplotype is the most common Y-DNA signature of Europe’s most common Haplogroup, R-M269. Simply put your ancestors have experienced a dramatic population explosion over the past 10,000 years, probably since the end of the Last Glacial Maximum (LGM-that’s Anthropology-speak for the last Ice Age) that covered most of Europe beginning 20,000 years ago and lasting for 10,000 long cold winters.
R1b, and its most common Haplotype (yours), exists in high or very high frequencies in all of Western Europe from Spain in the south to the British Isles and western Scandinavia in the north. It appears that approximately 2.62% in Western European males share this most common genetic 12 marker signature and because of its very high frequency we always suggest that for genealogy purposes people in this group should only use our 25 or 37 marker test for their genealogy.
Anthropologists have been describing for many years that only a select % of all the males in past societies did the vast majority of fathering, while other males lost the opportunity to pass on their Y-Chromosomal genes.
On a lighter note it’s clear that R1b’s Western Atlantic Modal Haplotype has contributed much more than its ‘fair share’ in populating Western Europe.