Quote Originally Posted by halfalp View Post
Well its clear already 5000BC that Pontic Steppe and South Caucasus are exchanging females via the mtdna results we have cf. ( H2a1 in Khvalynsk and H2a1a in Sredny Stog and maybe y-dna such as J1* in Karelia.
Yes, although this isn't really exchange, but signs of one-way traffic. If there was admixture between North and South of Caucasus populations, the two populations must have met, so I don't see why there would not also have been some gene flows in the opposite direction.

Quote Originally Posted by halfalp View Post
I dont think any R1b and G population ( together ) ever existed anywhere.
I think it likely, with G-PF3345 specifically - in the Eastern Balkans/Carpathians (and spilling over into Central/Western Europe) with L51, and in the Western Caucasus with Z2103. It might help explain why L23 and PF3345 are the only subclades of each haplogroup that thrived, and PF3345 provided what I expect living L23 acquired the majority of its Anatolian component from.

Quote Originally Posted by halfalp View Post
And i wouldn't take too much reltation from ancient dna distribution with modern one. I have already made the research and the L-L595 haplogroup from Maykop is nowadays mainly an European lineage especially extreme west europe as Ireland and British Islands but also Estonia. Wich tells us this lineage since Maykop expanded a lot, probably with IE speakers somehow.
Exactly, it seems to mirror R1b-L23. Probably not a coincidence, in my opinion.

Quote Originally Posted by halfalp View Post
I think there was infiltration in Steppe from the south both East and West of the Caucasus mountains. Even though the question is, Where did R1b-Z2103 originated?

Then there is that argument that Z2103 branches of Armenia separated before the Steppic and Eastern European ones. That's probably true, but it doesn't tell us where it did separated, Armenia is just the modern focal point, not the point of origin.
I think we are close enough to the answer - that its formative period came to a conclusion most likely somewhere near to the Caucasus. This fits with yDNA, mtDNA and aDNA evidence.

To expect much more than this is unrealistic. The formation of Z2103 as we know it represents several hundred years of lineage through a series of single individuals who underwent 10 different SNP mutations. It is impossible for us to find the remnants of each of these individuals, and track exactly where they were all conceived and where they travelled over their lifetimes.