I don't think it's quite like that. Yes, everyone in a region is likely related to ancestors +800 years ago from that region, it's not the same for regions wit

I don't think it's quite like that. Yes, everyone in a region is likely related to ancestors +800 years ago from that region, it's not the same for regions with little migratory exchange. Probably every Chinese person is a descendant of the 1st Han Emperor, but probably most Europeans are not, though they are probably all descendants of Charlemagne, whereas Chinese citizens are not. Etc.