I'm talking about the I1 specific mutations as well. yfull lists 301 mutations unique to I1, but that is not for the entire Y chromosome, only about 13% of it. You presented it as if those 301 are all the mutations, which isn't the case.
I'm going with the known mutations publicly available. Do you have a list for the rest? That would make me very happy.
Sweden has the highest concentration of I1 in Europe, and the population also has the most dolichocephalic skulls in Europe. Before nationalism Europe was populated by clans which did not necessarily interbreed.
Swedes have square heads and have the highest concentration of I1. But that I1 is only one branch, and the other main branches did not originate from the Scandinavian branch. The Basques have among the highest R1b in Europe but it has been proven that it's not their original Y-DNA group, but one of Celtic/IE expansion. Look at any PCA chart of Europeans. The Swedes are not some special and magical branch. They cluster right by the Danes and Germans, the same as any other geographical neighbor in Europe. They did get BIG and they did become fearsome Vikings having mostly I1 Yhgs. After looking at the tree again and the estimated formation dates, check this out:
I1 (final mutation 4600 ybp) -> DF29 (4600 ybp)
West German -Z58 (4600 ybp) ->Z59 (4600 ybp)
German/East German -Z63 (4600 ybp)
Scandinavia -Z2236 (4600 ybp) -> L22 (4100 ybp)
There was rapid geographic expansion of major I1 branches. Being as Z63 is rarely found in Sweden and L22 is mostly confined to the north, we know that either one did not originate in the homeland of the other (at least in a significant population).
It seems to me that "Mr. DF29" may have been a powerful king and he had 3 sons (or brothers/grandsons) to rule three zones who were all prolific. Similar to Alexander's generals or Charlemagne's sons, or perhaps just three related tribes that had to spread out and were led by sons. The map on this site for Funnel Beaker culture looks like the zone we are interested in. The date range for it ends at 2650 B.C. That almost perfectly coincides with the formation of D29 and the "big 3" subclades. This is about the time of the Battle Axe culture and the Corded Ware as well. Somehow the "big 3" took advantage of these changes and came out on top.
The Scandinavian branch of I1 persisted and proliferated more but that may be due to R1A and R1B incursions on the mainland. For example, the Franks slaughtered a lot of Saxons. If the Saxons had held their ground would we see similar proportions of I1 in Germany as we do in Sweden?
"they" would be some scientists I don't remember the name of who proposed the theory in some science article. I think it's a prevailing theory though. I think I1 and I2 are believed to have co-existed in Europe as hunter-gatherers before the arrival of farmers.
It seems that the theory makes sense but that I1 was first found in an EEF population in Hungary. This leaves a lot of questions on the table. We don't have another good I1 sample for a very long time, and I'm looking them up as time allows.
That wasn't the point. Lets take lactose tolerance for example, did the milk drinkers commit genocide on those who didn't drink milk?
Lactase Persistance is a huge survival advantage. HUGE. This is completely different than eye pigmentation which as far as I know, doesn't grant any special abilities other than attracting mates based on beauty.
If that was the case, wouldn't we see similar behavior in mtdna haplogroups?
No, we see European populations get completely turned over on the Y-DNA side but retain mtDNA, such as the Basques.