I've been finding U106 STR diversity as young in Scandinavia, when compared to the Low Countries, the rest of Continental Europe or the British Isles.
Perhaps there is an alignment with expansions of U106 and Germanic languages, but not necessarily out of Scandinavia.
Mike, I'm sure you've posted this somewhere before, but what is your variance/diversity figures for U106 in Scandinavia, Germany, Poland, and England? Can you vis-a-vis them with P312 figures too? I guess I'd like to know roughly what time P312 is thought to have arrived in Scandinavia, and see how U106 compares.
I'm keeping an open mind on U106's movements from its beginning. Despite these brothers being almost the same age, it seems inconceivable and quite amazing is that P312 had a 2000 year old stranglehold on much of western Europe to the exclusion of his U106 brother, but that may well be the case...
With the neolithic farmers picking the eyes out of coastal mediterranean areas and hopping along the coast to estuaries of rivers, did P312 perhaps do the same, whilst U106 overlanded it much more slowly, and by the time they reach say Denmark, P312 is firmly entrenched with no niche for U106 to fill or exploit. Does P312 take the wives and cattle of the neoliths, unburdened by having to drive its own cattle overland like U106 to the north?
Perhaps P312's stranglehold over the Atlantic Fringe was not so much a stranglehold but just that U106 was far away from the Atlantic and found benefits in working with indigenous populations than in working
with his own brothers. (BTW, "working" may not be appropriately descriptive.)
Perhaps this is not a P312 versus U106 issue but just the nature of the expansion of the L11 subclades. By that I mean let's consider down a level or two on the L11 family tree, and let's consider that L11 is a family of a sort. It kind of looks like U152 ran up and down the Rhine valley down into Italy. L21 seems to have been predominate in Atlantic areas, particularly the northern ones. Meanwhile Z196's lineage was more successful in Iberia but also scattered quite a bit all over along with some P312* forms. U106's Z381 and Z18 probably had slightly different distributions too to the east of most of the other L11 subclade expansions.