K1 is a haplogroup that branched off a more ancient one about 35, 000 years ago.

FORBES: Portrait of an Irish Genotype

My paternal haplogroup (R1b1b2a1a) turns out to be from the most common in Western Europe.

FORBES: Portrait of an Irish Genotype

And only about 19% of the Early Neolithic remains from Central Europe belonged to the H haplogroup.

BBC: Making of Europe unlocked by DNA

Population growth and migration from western Europe may have driven up the frequency of people carrying haplogroup H.

BBC: Making of Europe unlocked by DNA

Broadly speaking, a haplogroup is a family of similar haplotypes that share a common ancestor with the same genetic mutations.

FORBES: Portrait of an Irish Genotype

Sub-types of haplogroup H that are common today first appear with the Beaker people and the overall percentage of individuals belonging to the H clan jumps sharply at this time.

BBC: Making of Europe unlocked by DNA

That distribution suggests that some of the first men to bear the haplogroup in their Y-chromosomes were residents of Doggerland, a real-life Atlantis that was swallowed up by rising seas in the millennia following the Ice Age.

FORBES: Portrait of an Irish Genotype