Simon Kirby - The Language Organism: evolution, culture, and what it means to be human.
The video talks about "a new kind of evolutionary system". There's a discussion of "shielding" 35 minutes in.
32 minutes in, Simon says:
One way to think about this is to sort-of turn things on their head and, rather than think about us being adapted to language biologically, rather language is adapted to best survive in us. In order for language to get passed on and to work it has to be learnable by children - and that is the adaptive force at work in the explanation of these structural features - and this has led a number of researchers to suggest that language itself can be seen as an organism whose environment is our brains. Whether you can really make that analogy work, I am not so sure - but it's highlighting the point that you can look at language from this other perspective and understand the features of it.
This is very tentative material. To understand culture, you have got to grab this perspective by the throat - not tiptoe around it and call it an "analogy".
Oh, and it's not "The Language Organism". Languages are composed of many words, each one of which may be acquired from different individuals (or multiple individuals). So your language typically comes from many cultural parents in many organic hosts - except for those few who live alone on an island with their mother. So: language isn't well modelled as one organism, but rather many organisms, each with their own inheritance pathway. Our symbiosis with languages is more like our symbiosis with lettuces in that respect - lots of words are involved - just as lots of lettuces are involved.