Darwinism is a set of movements and concepts related to ideas of transmutation of species or of evolution, including some ideas with no connection to the work of Charles Darwin. The meaning of "Darwinism" has changed over time, and varies depending on who is using the term. In the United States, the term "Darwinism" is often used by creationists as a pejorative term in reference to beliefs such as atheistic naturalism, but in the United Kingdom the term has no negative connotations, being freely used as a short hand for the body of theory dealing with evolution, and in particular, evolution by natural selection.