A new poll released just in time for Charles Darwin's 200th birthday found that only 39 percent of Americans say they "believe in the theory of evolution," and just 24 percent of those who attend church weekly believe in that explanation for the development of life on Earth.
The Gallup survey, released Wednesday, found a quarter of those polled do not believe in evolution, and 36 percent said they don't have an opinion either way.
Another survey by the Pew Research Center got similar results.
The Gallup poll of 1,018 American adults found strong ties between education level and belief in the theory of evolution.
"Among those with high-school educations or less who have an opinion on Darwin's theory, more say they do not believe in evolution than say they believe in it," Gallup found. "For all other groups, and in particular those who have at least a college degree, belief is significantly higher than nonbelief."
Just 21 percent of respondents who had up to a high school level of education believe in evolution, compared with 74 percent of those with postgraduate degrees.
Frank Newport, Gallup's editor-in-chief, wrote that attitudes were shaped to an even greater degree by religion.
"Previous Gallup research shows that the rate of church attendance is fairly constant across educational groups, suggesting that this relationship is not owing to an underlying educational difference but instead reflects a direct influence of religious beliefs on belief in evolution," he said.
Among weekly churchgoers, only 24 percent said they believe in evolution, while 41 percent do not and 35 percent have no opinion.
Inversely, 55 percent of those who seldom or never attend church expressed belief in evolution, while 11 percent do not, and 34 percent have no opinion.