Science Avenger has an excellent post about evolution and social Darwinism and why, in reality, social Darwinism is anti-evolutionary. He makes several very good points, the first of which is that the phrase “survival of the fittest” is really a misnomer that often leads to muddled thinking:
It is simplistic and misleading to talk of “fittest”, because it implies that “fittest” is an absolute objective trait of a being that we can measure and use to predict survival. Fitness is completely dependent on the environment. For example, take dogs and wolves. By any objective, contextfree analysis, wolves are more fit than dogs: they are, on average, larger, faster, tougher, and smarter. Yet dogs greatly outnumber wolves, due in no small part to forming a semi-symbiotic relationship with the most dangerous species on the planet: us.
Second, that even if one were to take evolution as prescriptive rather than descriptive and decide that we need to help out natural selection with artificial selection, the result would actually make the species less likely to survive, not more:
There is also a more generic argument against social Darwinism. If we were able to successfully breed ourselves into some sort of supermen, we would reduce the genetic variation of the species. This would greatly increase our exposure to catastrophic events, such as disease. If there is any normative value from evolutionary theory, it is that heterogeneity is good.
Both very good arguments.