The main concern of the first eugenists, such as Karl Pearson and Walter Weldon of University College London , were the perceived intelligence factors considered to be correlated with the social class. In his speech "Darwinism, Medical Progress and Eugenics", Karl Pearson equates eugenics with a field of medicine. Some areas of medicine that are not commonly recognized as eugenic affect the human genes background. These include sterilization and surgical techniques that allow the functioning of reproductive organs. Even medicines that do not directly involve reproductive organs can alter the gene pool. Genetic abnormalities in such individuals are thus duplicated, modifying the genetic background. On this basis, such practices are widely accepted as more radical eugenic processes.