For example, Aristotle, a famous academic authority, said: "Eggs can hatch birds, but birds cannot be born from a primitive egg, or a primitive bird must lay this egg.

There is an egg first, and the chicken hatched from the egg is still a chicken, but the egg laid by the chicken is not an egg. All life is connected and constantly changing. So the chicken was born in the egg cycle from generation to generation. This is based on Darwin's Origin of Species. However, in recent years, many new theories have appeared on this issue.