I would connect I2a2 with Swiderian culture (paleolithic Poland), maybe coming from the epigravettian Adriatic. Lepenski Vir may also have come from the epigravettian Adriatic, but they would have gone extinct.
All possible, still very speculative. One concern I have with placing I2a2 in Poland is that its two modern clades seem to have highest diversity around Germany. Of course, the center of diversity could have moved, but it leaves a slight reservation, and makes me lean more toward Ahrensburg.
Is there evidence that Swiderian came from the Epigravettian, by the way? I thought it was linked more closely with Franco-Iberian type cultures like the Solutrean and Magdalenian. The Epigravettian didn't seem to like to cross the Alps.
The I2a1a - I2a1b is split hard to explain. I2a1a seems to have expanded from Sardinia, maybe 8000 years ago, while I21b might be southern Slavs coming from around northern Ukraïne.
I really doubt I2a1a expanded
from Sardinia. It surely expanded
into it based on
Sardinian phylogeny. I'd guess France instead.
I2a1b has a subclade with an apparent major Slavic expansion (I2a1b3a going by ISOGG), but it also has plenty of subclades with greater diversity elsewhere. Its other subclades seem to have high diversity in Britain and Germany, with a known outlier sample from Iraq (just to confuse us more). I2a1b is really tough to pin down.
IMO, the give away is that I2a1a and I2a1b actually didn't branch away from each other directly. The branching event was rather between {I2a1a, I2a1*-NF, {I2a1c, I2a1*-Alpine}} and {I2a1b, I2a1*-F}. The first indeed seems to have its highest diversity in France, with the I2a1c branch perhaps pulling us just a little east. The second helps show that the original location of that branch was probably not too far away from I2a1a's origin, because the other member of that group is French.
I2b and I2c are small tribes now, difficult to say something about them.
I2b phylogeny is very poorly studied, but I think there's something to say about I2c yet, like that I2c-PF3881 has an apparent minor association with Celtic expansions, and I2c* has a more eastern tendency, with interesting apparent expansions in the Caucasus and Anatolia (largely among the nobility interestingly), among Eastern European Jews, and within the former Venetian Republic. Extrapolate backwards and link it to its largely Adriatic I2b cousin, and the branch looks a little more likely Adriatic than Franco-Iberian to me. But its split in diversity between both sides of the Alps muddies the water a lot.
What do you think about the people from Franchthi cave, Greece 20.000 years ago ?
Would they have gone extinct? Or would they have belonged to another haplogroup - not I ?
That would be even tougher for me to guess than Spain. I'd lean "not I," because modern haplogroup I diversity isn't very strong around there. But then again, modern haplogroup I had to have come from somewhere to the east, right?
