This is a very debatable topic to be discussing and it's an unsolved dilemma. But as I like to say; a circle has no beginning. Regardless of this theory, I believe the egg was before the chicken. Eggs create chickens. There probably was a bird-like creature, genetically similar to the so called Chicken, and through DNA and genetics; the bird-like creature would have evolved, and laid the "first" chicken egg. But this dilemma is based on the way your mind perceives things.