A new study found that 40 percent of Americans accept the evolution theory, down from 45 percent over the past 20 years.
Among the nations examined, only Turkey had a lower rate of acceptance of evolution, with 25 percent accepting it and 75 percent rejecting it.
The percentage of U.S. adults who overtly reject evolution also declined over the past 20 years, from 48 percent to 39 percent. The percentage of those who were unsure increased from 7 percent to 21 percent.
Miller said contributing factors to Americans' attitudes toward evolution include poor understanding of biology, especially genetics, the politicization of science and the literal interpretation of the Bible by a small but vocal group of American Christians, livescience.com reported.