The chickens and eggs came together. They changed slowly over time into the species we know today. Technically, then, the egg came first because at some point an egg hatched into the exact variety of bird we know today.
Or, taken more generally, it was never asked "which came first, the chicken or the CHICKEN egg." Eggs as an invention far exceed the age of any creature currently living on Earth!
The chickens and eggs came together. They changed slowly over time into the species we know today. Technically, then, the egg came first because at some point an egg hatched into the exact variety of bird we know today.
Or, taken more generally, it was never asked "which came first, the chicken or the CHICKEN egg." Eggs as an invention far exceed the age of any creature currently living on Earth!