Seeing language from the DNA

[Jaska]

Alanarchae:

It depends what geographical area you are talking about. It would indeed be difficult in a busy highway kind of area of historical movements but there are other areas where DNA only shows one or two significant post-Neolithic population changes prior to the first linguistic/historical attestation of language . So the choice of when’s the later attested historical language arrived or evolved is very small.

Define “significant population change”? And why do you think that language shift requires such a significant population change? In any case, it only works to one direction: when there is a significant population change, the probability of a new language is high; but even if there is no significant population change, there is a possibility for a new language.

Also, can you give a concrete example of your method for tracing language through the DNA or material culture?

Alanarchae:

By the way I suspect isotopes may prove as important as DNA because there is clear evidence from the bronze age into historic times of the practice of the elites fostering each others children over long distances. Basically swapping their kids in infancy and then returning to their home tribe as young adults. That is a great way to ensure dialects among the elites stay converged/divergence is seriously slowed artificially. I actually think this is likely a key factor in at least some of the distributing of Celtic as a dialect spoken by elites. ie lots of temporary migration among the elites of bronze  age Europe where future kings and chiefs etc were fully immersed since infancy in the language, culture and beliefs of other tribes before returning home in adulthood more like a member of his foster tribe than his biological one. That imo, other than permanent migration, is likely the most important mechanism in language in later prehistory

Even in such cases we cannot see from the DNA or the cultural remains which of these languages truly prevailed: the assumed elite language or the assumed commoner language.