I plan on clan breeding using 3 clans of chickens and I am wondering how long this can go on without adding a new clan for new genetics. I keep reading conflicting statements. One site says it can continue indefinitely without needing outside genetics. Another site said no more than 5 years and another said a family successfully kept a flock of Rhode island reds for 90 years. Does anyone know more about this and have any real numbers? Thanks.