Dr. GURU speaks,
The evolution of a wild Indian or south-east Asian Red (Gallus gallus) or Grey (Gallus Sonneratii) Junglefowl to a Chicken can be traced back to a set of gene mutations which occured in the Egg of a female Junglefowl. The mutations manifest themselves to give what we would classify as a Chicken.
The Junglefowl does not turn into a Chicken half way through its life, it lays the Egg that gives birth to the Chicken.
The GURU must now sleep.
ImposingSnail
This question has always troubled me. Yes it is true that something not quite a chicken and something else not quite a chicken did something biological and created an egg from which a chicken would hatch.
But when does 'egg' become 'chicken'? This answer assumes that until it has hatched from the egg there is no chicken. When clearly in order to emerge from the egg the chicken must exist.
One could argue that the chicken forms within the egg and the egg is what is discarded once the chicken has hatched. But if that is the case then the shell which is later discarded is only formed after the female's strand of DNA (Also called, but not to be confused with, an egg. As they are clearly not the same thing.) has merged with the Male's DNA.
My conclusion is that the egg IS the chicken, therefore rendering the entire argument null and void.