That seems a fairly circular argument - after all, can you be afraid of something happening to you without knowing that it can happen to you? Anything with a fe

That seems a fairly circular argument - after all, can you be afraid of something happening to you without knowing that it can happen to you? Anything with a fear of asteroids or boogey monsters 'knows' that those exist. So I disagree that "even the most basic creatures understand this", even for very broad definitions where understand can be interpreted as 'act, instinctively or not, as they would should they have consciousness'. I suspect many understand pain and have a fear of pain (again, where very loosely pain is 'bad things' they have previously experienced). Death is often a corollary of that pain, so they will act similarly, but I don't believe creatures at a most basic level understand death. Having said that, this was a fascinating article on a topic that has interested me for years, so I'd love to see more research supporting either your thoughts or mine.