> the entire European population has been thoroughly blended for 100’s of years.

This is not true. There’s more than a bit of population substructure within Ireland. Norman and English names are over represented among Fine Gael politicians, Gaelic derived ones among Fianna Fáil. The people in the Northwest are visibly different than in Leinster, more red heads (Celts), more people who could pass as Spanish ( the pre-Celtic population).

And the idea that European populations have been thoroughly blended is absurd. If you walk into an Aldi in Limerick you’ll see the same as as in Leipzig albeit in a different language. The girl looks German, not Irish. And Norwegians don’t look like Portuguese.