>>17777347
Modern genomics don't reflect later developments we see today. You need to look at patriline Y chromosomes during that period. Nords certainly view themselves as Indo-European, so it worked in that regard. There certainly is a metaphysical aspect to it.
Regardless, R1b and R1a still make up the majority of Nordic haplogroups. Obviously Indo Europeans didn't replace and kill everyone they conquered, but they presented their culture at first through themselves as the ruling one which was universally adopted where Indo Europeans simply lacked manpower.
I1 is largely a mystery since this area was never all that settled to begin with. When IEs arrived the farming people were in decline and it wouldn't have been much of a challenge to entirely replace them, which probably happened since the Nordics present one of the few regions where IE heritage is over 50% meaning that women also migrated and successfully managed to pass on a significant part as a haplogroup to their offspring. Certainly women were already traded before then and that may contribute to some mixing between HG groups, but we have some evidence that the low population density there contributed to IE women also contributing significantly to the later genetic profile.
One idea is that I1 spread internally as part of the Corded Ware phenomenon when Eastern Scandinavians with significant Baltic HG descent and Western Scandinavians met, warred and eventually resulted the Nordic Bronze Age. The farmers were specialists and like the Dasyu had the initial technical advantage in resettling the North after the decline preceding to secure their male patriline even in IE society.
