Evolution establishes a "scientific" rationale for racism by extending the "great chain of being" to humanity. Just as animal species are ordered into a hierarchy according development, so too the "races of men" are described as being more or less developed than others. Evolutionists then extend the doctrine of survival of the fittest to humanity. Removing religious morality and replacing it with the laws of nature, they claim that just as the varieties of animals struggle to survive, so shall the varieties of man, with the strong dominating and destroying the weak.