You have a lot of pet goldfish in a tank in your living room.You started your fish colony a couple of years ago from just 4goldfish that were from the pet store (likely heavily inbred =verylittle genetic variation). One day you are cleaning the tank andnotice a new juvenile fish with an unusual red spot on his tail. Itis the only one in the population with this spot. What might beinfluencing this population? Why?