Which theory supported the view of economic conservatives based on natural selection?

The theory that supported the view of economic conservatives based on natural selection is Social Darwinism. This concept applied Charles Darwin's ideas of natural selection and survival of the fittest to human society and economics. Proponents believed that individuals and businesses that were more adept at adapting to their environment would naturally succeed, while those who failed to do so would decline. This line of thinking emphasized a lack of intervention by the government in economic affairs, aligning with the beliefs of economic conservatives who advocated for minimal regulation and support of those who they perceived to be less capable in the competitive marketplace.

The other options are distinct in their focus: Utilitarianism is a philosophical theory that promotes actions that maximize happiness and well-being. Classical economics lays out the principles of free markets and minimal government intervention but does not tie itself specifically to natural selection. Modernism refers to a cultural and artistic movement rather than economic theories. Therefore, Social Darwinism is uniquely aligned with the economic conservative worldview that incorporates Darwin's ideas into the social fabric.