It would be great if ancient DNA was ever able to shed some light on archaeological controversies such as this. It has already done so in Europe, where the discovery of a Mediterranean-like TRB farmer in Sweden destroyed theories of "acculturation" in the diffusion of the Neolithic economy into that continent, and I'm sure that similarly interesting things were taking place during prehistory in other parts of the world.
A couple of related recent posts:
Kaukasus und Orient: Die Entstehung des „Maikop-Phänomens“ im 4. Jahrtausend v.Chr.
[English abstract] Graves and settlements of the 5th millennium BC in North Caucasus attest to a material culture that was related to contemporaneous archaeological complexes in the northern and western Black Sea region. Yet it was replaced, suddenly as it seems, around the middle of the 4th millennium BC by a “high culture” whose origin is still quite unclear. This archaeological culture named after the great Maikop kurgan showed innovations in all areas which have no local archetypes and which cannot be assigned to the tradition of the Balkan-Anatolian Copper Age. The favoured theory of Russian researchers is a migration from the south originating in the Syro-Anatolian area, which is often mentioned in connection with the socalled “Uruk expansion”. However, serious doubts have arisen about a connection between Maikop and the Syro-Anatolian region. The foreign objects in the North Caucasus reveal no connection to the upper reaches of the Euphrates and Tigris or to the floodplains of Mesopotamia, but rather seem to have ties to the Iranian plateau and to South Central Asia. Recent excavations in the Southwest Caspian Sea region are enabling a new perspective about the interactions between the “Orient” and Continental Europe. On the one hand, it is becoming gradually apparent that a gigantic area of interaction evolved already in the early 4th millennium BC which extended far beyond Mesopotamia; on the other hand, these findings relativise the traditional importance given to Mesopotamia, because innovations originating in Iran and Central Asia obviously spread throughout the Syro-Anatolian region independently thereof.