You're misusing the "Ship of Theseus" concept. That has to do with individual identity. >at what point does it stop being a chicken, i.e. its parent. When it

You're misusing the "Ship of Theseus" concept. That has to do with individual identity. >at what point does it stop being a chicken, i.e. its parent. When it doesn't meet the genetic definition of a chicken, however you choose to define that. Once you have a definition, there will be a point in evolutionary history where such a creature arises. Anything before that is not a chicken, so therefore >is that itself the egg or the chicken-maker Once again, the answer is "the egg". A pre-chicken creature produced an egg that hatched the first chicken. Problem neatly solved.