PRINCETON, NJ -- The majority of Republicans in the United States do not believe the theory of evolution is true and do not believe that humans evolved over millions of years from less advanced forms of life. This suggests that when three Republican presidential candidates at a May debate stated they did not believe in evolution, they were generally in sync with the bulk of the rank-and-file Republicans whose nomination they are seeking to obtain. Independents and Democrats are more likely than Republicans to believe in the theory of evolution. But even among non-Republicans there appears to be a significant...