A reminder, these are non-rigorous philosophical musings, not scientific facts. This is an extended what if and should be taken as something of interest, not a definite scientific theory or anything like that. Certainly, it could be a start for actual scientific work, but it remains speculative, at best.
Previously, I argued that language is a living thing under a particular definition. It makes a lot of sense from a certain perspective. Languages change over time. In-part, this is because they do not replicate perfectly (children speak differently from adults). Languages are also like bacteria with plasmids, constantly exchanging pieces with one-another. If you view each language that we know of in the world, you can consider language to be a 'species', with each person's private ideolect being the individual elements of that species.
Now, if you know much about anthropology and linguistics, you know that language and culture are very closely related, almost the same thing - if not, then language is the vehicle for culture. Our musings on life make this have hilarious and far-reaching implications. Just as I argued that language is alive, I could similarly argue that culture is alive. Richard Dawkin's musings on "memes" could be considered alongside this. In this view, we are all living things with a symbiotic language in our head, that further has a symbiotic culture within it, a Matrushka doll of 'living' beings!
Naturally, one can wonder if these 'living things' evolve. I would suspect that they would - in the sense that they would change as they replicated. I do not think that they would evolve in a Darwinian manner. I do suspect, however, that because of the symbioses involved, languages and cultures would pressure one another to occupy the most human minds, the most successful being those languages and cultures that most benefit our own living efforts to spread our genetic code. Under such pressures, the structures of languages and cultures might change and flux as a simple result of constant evolution towards changing conditions. I suspect, however, that while as the evolution of biological organisms has many oddities and strange paths, the evolution of languages and cultures would be even stranger and less predictable. Certainly a chaotic system in the mathematical and colloquial senses.