> We show that language isn’t isolated from political currents and that this dynamic has been a facet of human history for much longer than previously thought.

Um, when did anyone think it wasn't?

The entire history of linguistics shows this. Proto-Indo European had no common word (for that family) for sea/ocean [1] from which we can deduce something about the people who spoke it. That's not political obviously but environment and culture are inseparable from language is the ponit.

Languages really only grew for political reasons. Look at the spread of Latin throughout Roman territories.

Likewise, languages splinter and diverge in isolation. Populations that remain where they are and separate from others will drift linguistically. You can look at most of Europe for this. As just one example, the drift in Swiss Germany in Switzerland, which is a relatively small country.

But more than that, it takes some kind of centralization, which is to say, political force, to maintain a language. English had massive changes from Old English (which is essentially a separate language from Modern English) to Middle English (which is largely comprehensible by the modern speaker) when French was the court language of England in the centuries after 1066. And the Normans left their own imprints on English, which is where a ton of loan words came from [2]. But English grammar also greatly simplified without a central authority telling everyone what is proper, basically [3].

One of the fascinating things I remember learning was that there are between half a million and million cuneiform tablets int he world and fewwer than 10% of them have been translated. Now cuneiform is a writing style but one of the difficulties is that it encompasses multiple languages. And this was one of the earliest recorded examples of language displacement from Sumerian to Akkadian over thousands of years. But tablets could be written in part in both languages for a very long time. This is where we have the earliest documented human name, Kushim [4].

But the point is that the rise and fall of Sumer and its displacement by Akkad is recorded in the language.

And of course we had the spread of "colonial" languages in the colonial period (ie Spanish, French, Portugese, English).

Pragmatism also is a factor here. Different languages are inconvenient between populations that interact. The natural tendency is to homogenize on language given sufficient time, even without political pressure. it's a little sad when languages die but it's kind of inevitable.

[1]: https://talageri.blogspot.com/2020/05/the-proto-indo-europea...

[2]: https://www.krysstal.com/display_borrowlang.php?lang=Norman+...

[3]: https://www.sciscanpub.com/index/journals/ainfo/alr/7943.htm...

[4]: https://en.wikipedia.org/wiki/Kushim_(Uruk_period)

Study uncovers lost 'golden age' of languages