Adding up to previous posts, I'd answer the following.
It may have expanded the Italian cluster up, but it didn't do the same with the NW towards South (I see you mentioned F&G though). Some %s have been always there. In our case in specific, it looks like 23andMe re-accommodated most of the Broadly components and also those minor that usually showed up (at very low %s). For example, my mother's NW hasn't changed substantially (it decreased from 42.2 to 41.9); on the other hand, the F&G per se jumped from 34.8 to 41.9, i.e., now all the NW % are F&G. My father's increased a bit though, whereas mine decreased.
I see that you're also referring mostly to the "dissonance" between results from relatively close areas, and to how these results are established. Good question! One of the issues of myOrigins imo is precisely this lack of coherence between results from people with very similar ancestries. I don't think it helps in interpretations.
Agreed. That's roughly what I was suggesting in this thread:
https://www.eupedia.com/forum/thread...German-Descent
I believe in some Roman influence, shifting them a bit South(east), followed by some influence from the Germanics, shifting them back a bit North.
And I wonder if there was an additional Southern input to Venezia at the times of Serenissima. Possibly.
As for the internal variability in North Italy, agreed, but it's also true there would be a considerable similarity. And there's also some similarity between N. Italians and, say, Central Europeans or Central Italians, but I think that in genetic sense North Italians are simply... North Italians. :) As such, they must be distinguishable from Central Europeans for the most part, and now we must mention Ancestry.com. In my opinion it's doing a great job with North Italians, including NE Italians. For example, I know about a guy from the mountains of Udine who scores almost 80% for N. Italy (69% Northern Italy plus 10% Northeast Italy, Croatia & Bosnia and Herzegovina). It seems to reflect the fact he fits better to the North Italian cluster than to any other, or that he's much similar to other North Italians than he is to other pops, in genetic sense. Still in AncestryDNA, "Germanic Europe" in North Italians looks more realistic, apparently more in line with actual Germanic influence into the area.
I don't think these results defy the Italian cline concept, if we consider the (commercial) goals of the company, the purpose of identifying very recent ancestries. For example, AncestryDNA does distinguish certain Italian clusters, but they could unify them in one (Italian) cluster if they wanted. For the good or not, 23andMe just has a different approach. We could think on a calculator working with continental level. The fact this calculator is able to distinguish most of, say, European and Native American influences doesn't imply that Europeans are genetically the same, nor Native Americans.
If we think 23andMe should divide Italian cluster into three clusters, as AncestryDNA does, that's ok. What I'm saying is basically that what 23andMe is doing doesn't seem "magic". Now, I agree that it could work better some North Italian groups, make more sense of them, which would demand more reference samples. That seems a consensus here.
I have 4 siblings, some of them could be more Northern shifted than my parents, some could be in between, and some could be more Southern, as myself. It pretty much depends on which parts of their DNA were inherited. Seeing results from several calculators, it does seem I'm a bit shifted South compared to them, but I think this difference in 23andMe is partly explained by phasing, which would increase accuracy.
@Angela
Despite some of these Venetians are more shifted South or North in 23andMe or other commercial calculators, sometimes substantially, they don't necessarily plot that differently in some PCAs. For example, that woman with 4 grandparents from San Vito di Cadore scores 48.5 % Italian and 50.5% F&G in 23andMe, however, her K15 results are not that different from my mother's. They plot closely at the related PCA. Then she belongs to N. Italian cluster. The neighbor Austrians from Tyrol must be much more Northern shifted than her.