North Africa is pretty likely because of what we in Ireland call the 'Gulf Stream', though I think it's more correctly called something like the Continental Drift. This is a strong, warm tide that sweeps up along African and past the west coast of Ireland, and was always a great sea-road for us.

As far as I know, the genetic evidence is that Ireland and Britain have virtually identical profiles.

I've always noticed how very much like us the Slavs look; you wouldn't know where *that* came from.