I had one of those DNA things done in order to lay to rest family lore that one of my ancestors was Native American. It turned out that we had nary a smidgeon. All Scot, Irish, British, Saxon, Norman, and Scandinavian, about as white as white can be...with one exception. There was a tiny trace of DNA from the Caucasus. Since then I’ve been scratching my noggin trying to figure out how that might have happened. This map may explain that.
Something to remember...in ages past when Romans were conquering everything around the area of the Med. and into Europe...once conquered, subject people became property of the Romans and whole populations were moved around as they were sold/traded.
I remember reading Gibbon who said that toward the end of the Empire, there was not enough gold/silver etc. for the valuation of commodities and slaves became currency.
It sort of explains how/why genetic stuff may be confusing
There seems to have been a prehistoric migration from the Caucasus/eastern Asia Minor region (where agriculture was first developed) into Europe, which would account for Europeans having a bit of DNA from that region.
During the Ice Age, Scandinavia was under an ice sheet. Later it was repopulated in part by people moving north from the Balkans...but that may have been earlier than the invasion of southeastern Europe by Anatolian farmers.