Scotland never recovered genetically from losing 1/2 of it's young healthy men in the Battle of Flodden in 1580. The heirs of the survivors eventually died in the trenches of The Somme and then in N. Africa, France and Germany.
It's a small population where a great portion of healthy males were killed before they had children. The ones who did were the guys too unhealthy to fight for Britain or emmigrate to America.
What you say is interesting. Something to think about.