It's a fascinating emergent behaviour but also one that could have been predicted?
I'd imagine that our brains have become similarly biased towards generating such a generalised symbolic structure over hundreds of millions of years of evolution?
I'm thinking how certain regions of the brain reliably represent things like motor skills, speech, abstract thought.
I agree. In retrospect, this seems almost inevitable. And our own minds at least to do some form of symbolic reasoning — literally language, which you are apparently capable of, dear reader, as a lower bound. There might be more symbolic reasoning in the conscious, unconscious, and subliminal parts of the mental workspace. I always hesitate to infer similarities between the brain/mind and LLMs, but I certainly track the comparison here.