So I'm almost certain that Cro-Magnon were hg. IJ folks. But R* folks belong absolutely to a different lineage. What kind of species were that Homo sapiens?
Both native Europeans (hg. I1 & I2 folks) and native Middle Easterns (hg. J1 & J2 folks) were all descendants of Cro-Magnon, but who was the new newcomer that had R* lineage and migrated into West Eurasia?
as said yet by someones, it would be necessary to know what is 'Cro-Magnon' man: for somebody it's every paleolithic man or every european paleolithic man. But paleolithic men was diverse, there was more than a lineage. When I say (without trying to do a rule for the others) Cro-magnon, I say a phenotype that was found in Perigord Dordogne France before the LGM, with a serie of very homogene others phenotypes very close to him and forming a family with him. The Grimaldi people seam to have been a close population but more heterogene and with some negroid traits ON SOME OF THEM. The French CHARLES thought it was a variety of Cro-magnoid with some negroid details that came to Europe form Egypt or near Egypt. It could be either negroid admixture or features kept in a phenotype not completely evolved on the way to Cro-Magnon. The 'negroidism' depends on the specimen choosed to establish the paradygme -
But in the vicinity of well definite Cro-Magnon phenotypes lived also other phenotypes very different in features, (I 've in mind the Brünn and Combe-Capelle types that had maybe evolved in descendants differents from those of Cro-Magnon, brachycephalized or not). the only common point being the robustness of skeletons. It's sure for me that is was yet distinct lineages separated for a long time that met back in France at this time (not a douzen!!!). The same in Germany and Bohem (Brno/Brünn), where crossings became common. What is a pity is that they all won the name of 'cro-magnoid' even when they didn't share any immediate relationship.
I hold that it remain some almost unchanged descendants of the former form of Cro-magnon (the precise type of Perigord), just a litlle gracilized, not too much, and tha they are to be found in Wales and in general from the the Atlantic coasts to the North Sea coast, even if they could be found somwhere else. That 's not to say there are not other evolved descendants of Cro-magnon (someones looked at them as 'Borrebys') living side by side with them today. some occidental pseudo-'mediterranean' types too could be far cousins to these 'borrebys' , with a opposite evolution in a different environment, on 20 years.
coming back to HG's, I keep on option the possibility that some Y-I (ancestors of the precise Y-I2a1:Sardinia, Spain, Atlantic Coasts) was perhaps living in Western Europe not too far from some Y-R1b (close to R-P312 or not too far upstream) present here and there
at low numbers (preventing the next mutations that 'll came far after) before the LGM and a first demographic explosion.
for metrics, the 'danubian' pseudo-mediterranean' type is far as a whole from these 'grimaldi' types, and closer to the ethiopian types, diminished and evolved (Chamitic? Y-E1b?) - these last are very far form the true negroid phenotypes and closer to Arabs mediterraneans for I know-
The same reasonment can accept the possibility of others Y-I (ancestors of Y-I1, Y-I2a2, I2b and scattered too) between Bohem and Ukraina, maybe the Eastern Caspian shores, and in the Eatsern Europe or Caucasus r from some Y-R1b (upstream to the central Europe derivees, cousins stayed there): we are too sure of a homogene geographic block of descendants of a same lineage on a long scale of time.
just some speculations and with respect
M