Earlier quoted context omitted.
A zoo is still a zoo if there aren't any animals in it, but it wouldn't stay in business very long. No matter how important the animals are to the long-term viability of the zoo, they are not the zoo. My gut bacteria may be vital to my survival, but they are not me. I don't find placing that line to be difficult at all.
> A zoo is still a zoo if there aren't any animals in it Is it? Identity is an interesting thing. To use a commonly-cited example-- if I swap out the muffler of my car and toss the original in the backyard, I think most would say I am still driving the same car. If I do the same with the front left tire, it's still essentially my car. Even if replace all four tires, same. But what if I swap one part a day with a repl…
So my response to your car example is that both vehicles are "the same car" since both get you around and both are owned by you.
In that sense, as your behaviour changes so does your identity. If you were able to 100% accurately encode all the actions you could ever take into a Markov Chain, then I would argue that Markov Chain is what makes you "you" at that point in time.