Do you realize how inappropriate it is to ask whether the chicken or the egg came first?

@est Annoying question, since no matter where you draw the line between chickens and the bird that it evolved from, that bird hatched from an egg.

@mikemccaffrey
depending on what you mean, the answer is trivial. if you mean, "did eggs exist before chickens," then, obviously, yes.

if you mean, "did chickens exist before the first chicken egg," it's an ill-posed because so-called speciation events involve populations of pre-existing species. the creatures that produced chicken eggs must have been more or less continuous with what came before because otherwise you just don't have a way to get to the chicken. you'd have to pick some arbitrary dividing line in the evolutionary history
@est