by Susan Jacoby

Today is the anniversary of Charles Darwin's birth (the 199th, as it happens) and, as usual, scientists around the world will hold ceremonies honoring the man responsible for the foundational insight of modern science - the theory of evolution by means of natural selection. In the United States, as usual, rational thinkers will struggle to explain why fewer than than half of Americans accept the scientific validity of any form of evolution.

The widespread American skepticism about evolution is a phenomenon unique in the developed world, as is the controversy over whether evolution or religious theories of creation should be taught in public school science classes. The usual explanation for this anomaly is the equally anomalous (again, in developed countries) persistence of fundamentalist religion in the United States. But that explanation is too simplistic and leaves out what may well be more important - the American public's low level of scientific knowledge, independent of religious beliefs and completely at odds with America's image of itself as a world leader in education, science and technology.

In 2006, a Gallup Poll found that only 30 percent of Americans continue to believe in the literal truth of the Bible, with its six days of creation - a 10 percent decline over the last three decades. It is difficult to reconcile that finding with the results of a 2005 poll by the Pew Forum on Religion and Public Life, indicating that only 48 percent of American adults accept evolution (even if guided by God) and only 26 percent are convinced of the validity of Darwin's theory of evolution by means of natural selection. If only 30 percent believe that the Bible is literally true, why do so many more Americans reject the evolutionary theory considered settled science in the rest of the developed world?

The answer is ignorance - and Americans may be no more ignorant about evolution than they are about other aspects of science. According to surveys conducted for the National Science Foundation over the past two decades, more than two-thirds of adults are unable to identify DNA as the key to heredity. Nine out of 10 Americans - nearly 63 years after the United States dropped the first atomic bomb on Hiroshima - do not understand what radiation is or its effects on the body. One in 5 believes that the sun revolves around the Earth.

This knowledge deficit has nothing to do with religion, but it does point to a stunning failure of American public schooling at the elementary and secondary level. One should not have to be an intellectual or, for that matter, a college graduate to understand that DNA contains the basic biological instructions that make each of us a unique human being or that the Earth is not the center of the solar system.

The most recent assessment by the Organization of Economic Cooperation and Development, a Paris-based agency that conducts regular education evaluations in the world's most industrialized nations, found that American 15-year-olds ranked 24th out of 29 countries in mathematical literacy (and it is tough to understand science without basic competency in math). In science, the United States is not among the worst performers but is merely mediocre - 14th out of 25.

There is, of course, a relationship between the strength of religious fundamentalism in any given state or local community and public school biology teaching. The American tradition of local control of schools ensures that in areas with a strong fundamentalist presence, biology teachers will always be skittish about offending the religious sensibilities of biblical literalists.

Keeping religious theories out of public school science classes is not enough. Defenders of rational thought must expand their focus to the much more general problems of scientific and mathematical illiteracy.

The United States desperately needs national curriculum standards - as opposed to standardized testing that reflects the different and often defective norms of different states. Americans, as a people, need to understand that the sacred cow of local control of school curricula has put our students at a competitive disadvantage with children from France to South Korea.

In 2009, the inauguration of a new president will coincide with a critical scientific milestone - the 150th anniversary of the publication of Darwin's "On the Origin of Species." The nation desperately needs political leaders who understand the importance of ensuring that wherever Americans live and whatever religious beliefs they do or do not hold, their children must be well educated by modern scientific, secular standards and able to compete in a global economy.

Susan Jacoby is the author of "The Age of American Unreason" (Pantheon, 2008).
© 2008 Hearst Communications Inc.