by Alexander Zavialov

The practice of exogamy stems from the Proto-Indo-Europeans.

The Western offshoots à la Corded Ware remained isolated from the rest of the world and the practice fortunately faded out of existence. You still had Bell Beakers invading Iberia and Italy and thus producing modern Spaniards and Italians.

But Northern Europe was relatively unpopulated compared to the rest of Europe, which allowed the Corded Ware culture to create a very homogenous pan-North European genetic cluster which has persisted without change for the past 5000 years or more.

That’s probably a world record.

They were probably helped in eliminating exogamy by the cultures of the Early European Farmers that they encountered and mixed with – although there was no more mixture after that!

Then there’s also the fact that General Cognitive Ability started increasing after this final admix event, which cemented the modern North European cluster.

Perhaps they were getting too smart and no longer considered their foreign neighbours to be viable partners.