The Papuan kingfishers living in the mainland of New Guinea show little variation in bill size, tail feather length, and structure. The isolated population of Papuan kingfishers living on nearby islands differ from each other and from the mainland kingfishers. Which statement would be the most direct reason that island kingfishers have greater variation as compared to the mainland kingfishers?

i have absolute no idea

Explanation:

fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes (salts in solution) in the various body fluids are kept within healthy ranges. the core principle of fluid balance is that the amount of water lost from the body must equal the amount of water taken in.