This is too dependent on what you mean by "unique", though. What do we have that apes don't, and which directly enables intelligence? What do we have that LLMs don't? What do LLMs have that we don't?

I don't think we know enough to definitively say "it's this bit that gives us intelligence, and there's no way to have intelligence without it". We just see what we have, and what animals lack, and we say "well it's probably some of these things maybe".

> What do we have that apes don't, and which directly enables intelligence?

Again, there are multiple fields of study with tons of amazingly detailed answers to this. We know about specific proteins, specific brain structures, we know about specific cognitive capabilities in the abstract, etc.

> What do we have that LLMs don't?

Again, quite a lot is already known about this.

This feels a bit like you're starting to explore this area and you're realizing that intelligence is complex, but you may not realize that others have already been doing this work and we have a litany of information on the topic. There are big open questions, of course, but we're definitely past the point of being able to say "there is a difference between human and ape intelligence" etc.