When I was a Christian, one of my justifications for Christianity was that I knew the answer to this question. Of course, the Chicken came first since god created mature animals, not infants, eggs or larvae, so it had to be the Chicken. I was proud of myself for figuring that out.
Of course, since now I know that the Bible was most likely fictitious, we have to fall back on evolution, and the answer to the question becomes slightly more convoluted. Which came first- the chicken or the egg? The egg, because mature animals can’t mutate their DNA as much as newborns, i think.
but the first living thing on earth that could be defined as chicken must have had to have been mutated within a pre-chicken’s eggs, thus the egg came first.
Of course, that is assuming we take the question of which came first chicken or egg contextually and assume that by that question we mean which form of chicken came first.
yet, nevertheless if you mean literally chicken or the egg, its still the egg that came first. dinosaurs had eggs way before chickens existed, so there. tada.
I’m such a scientist, this information I’m disseminating in this blog will surely be constructive in the progression of mankind. Surely the answer to the question of Chicken or Egg must have some practical purpose?