Population dynamics in North Caucasus.
From already published papers we know that North Caucasus had two distinct populations that most of the time had little interaction with each other.
One was in plain/steppe parts of North Caucasus (here after NC). This Steppe NC was connected to Eurasian plains in the North. The second population was living on the Northern slopes of Greater Caucasian range. It had South Caucasian origin and they settled there mostly after the Eneolithic. (after 4500bc). Currently there is no evidence that those northern slopes were inhabited in Mesolithic and even in Neolithic.
This dichotomy was so pronounced that it was present in Maykop culture which was an unified culture between Steppe and Mountainous NC, but still inhabited by two distinct populations. The Steppe Maykop (Q,R1) which was of Siberian origin and Mountainous Maykop related to Leyla-tepe (L, T, G2, J2b2a?).
When Yamna formed (3300bc) and started to expand, it moved to South also and conquered the lands of Steppe Maykop practically replacing them without mixing. There a new culture formed which usually is labeled North Caucasian culture ( first map the blue culture ) but a less confusing name is the Kubano-Tersk. We have ancient DNA from Kubano-Tersk people and they were predominantly R1b-Z2103. Genome wide ( autosomes ) they were identic to Yamna.
After 2800bc Yamna transformed into Catacomb culture with the same Y DNA. Catacomb culture had a strong influence on Kubano-Tersk which is not surprising because they were kinsmen. It basically absorbed it. Was this absorption due to cultural influence or there was another migration is not clear.
You can see that on the second map. Then one group of unknown part of Catacomb culture moved to South Caucasus via Daghestan no later than 2400bc. We discussed a lot this event.
Hrach Martirosyan once expressed an opinion that Armenian do show evidence of archaic contacts with Abkhaz-Adyghean languages who are usually associated with Dolmen culture. If that is true then it must have occured during that Catacomb period or slightly later.
The catacombicized Kubano-Tersk culture continued to evolve and it started to mix with neighbouring Mountainous NC who where predominantly J and G. This gradual mixing will lead to the formation of Koban culture (1300-400bc)
At 2200bc Catacomb culture ends and two new groups appear in his place. One is called Multi-Cordoned ware (2200-1800bc) which was mostly in Pontic Steppe while the other is labeled Lola. Lola was in the West of Caspian sea. The remarkable thing about Lola is that it was a partial resurrection of old Steppe Maykop people who were of West Siberian origin. We don't have ancient DNA from Multi-Cordoned ware. But in most likelihood it was similar to Catacomb with some possible influences from Carpathian mountains. There are some serious reasons to believe that Multi-Cordoned ware was speaking some kind of Balkanic languages. Some even proposed a link with Mycenaeans but with current data it's unlikely. For us it can represent interest if we learn that the I2c2 in Armenia and E-V13 in North Caucasus are related to this culture activities.
(to be continued...)