Explain the concept of racism and social Darwinism and how they relate to the policy of imperialism

Social darwinism seeks to use Darwin's theory of evolution to account for the success and dominance of certain humans and human groups in comparison to others. This has been used to justify racism where racial groups are believed to be superior or inferior based upon their power or level of development. These two ideas were used to justify imperialism by "civilized" European states over "un-civilized" states of the developing world.