Wow, the question clearly un-answerable as in you say something but it turns out to be wrong. If you say the chicken came first it can be easily countered, the chicken is only becomes a "full" chicken when it's going to hatch or fully formed. If you say the egg came first how can the un-formed chicken get into a shell?
The question is... if the very first modern chicken came from the egg of something which was not a modern chicken, is that egg a chicken egg or not? I say the chicken came first.
1. Chicken must lay egg, meaning chicken came first. 2. Chicken must hatch from egg, meaning egg came first. Neither came first, I say!
Simple and only real aweser none, to get an egg, you need 2 chickens and if the Egg was first, then it will die because without a chicking keeping it warm it will die!
But that chicken that hatched that egg came from an egg that was hatched by a chicken that came from an egg that was hatched by a chicken that came from an egg that was hatched by a chicken that came from an egg came from an egg that was hatched by a chicken that came from an egg that was hatched by a chicken that came from an egg..... As was said, a cycle. A circle. No end to the riddle.
The chicken it is so easy...almost no believes in the fact that more then one chicken could have been there at the start.