In the real world, animals often cooperate, proving that the world is not made up of hunters and huntees.

General Zaroff justifies his treatment of the men he uses for sport by saying that they are inferior.  He takes a very Darwinian view of things.  Darwin postulated that only the fittest survive, and therefore would have agreed with Zaroff’s idea of hunters and the hunted.  However, in the wild it is not the strongest for himself.

Through these cooperative societies, Clutton-Brock sees parallels to human actions. Animals cooperate with each other in many ways that humans do. He also notes that that level of cooperation is more developed in man than in any other primates. (usatoday)

This contradicts Zaroff’s view.  In human history, we also do not hunt one another.  We basically have developed society over the centuries to be more successful, more comfortable, and more blissful.  Zaroff does not demonstrate an evolutionary precept, either for animals or for humans.  He is just justifying his own beliefs to explain why he does what he does.