calimac

I don't get what you mean by:

I mean, also hardwired into the human brain is the desire to put foreign objects in one's mouth, and chew and swallow them, which is an awfully weird thing to do, objectively considered, but which does serve a useful purpose.

I could google when the first alimentary tracts appeared in animals, but you're talking about a feature that developed at least a hundred million years ago.