Firing a human is a form of natural selection. The unit here is a human fulfilling a position (job function) instead of an organism, and the adaptation mechanism would be memes/lore/training surrounding it. The same could be done in an accelerated manner to LLMs with some kind of DNA-like mechanism related to weights. It is plausible that LLMs will be bred in the future for specific roles by how well they fit - kind of like continuous parallel finetuning in prod.

As I wrote this I thought - hey, they might gain the capacity to do the same to us humans - and we won't even notice.