When educators and corporate leaders bemoan America's scientific illiteracy, they're usually referring to how we're losing our competitive edge in science and technology (see, for instance, the 2006 report from the National Academy of Sciences, "Rising Above the Gathering Storn,") or to the fact that fewer than a third of adult Americans know that DNA is the molecule of heredity, that only 10 percent know what radiation is and that 20 percent think the Sun revolves around Earth. But more and more, scientists grappling with the question of what you need to know about science to participate in civic discourse are concluding that the need is more fundamental: you need to know what science is, what it is not, and what it can and cannot answer.

And on that, there is ignorance at the highest levels.

When three Republican presidential hopefuls raised their hands during the recent debate to indicate they "didn't believe in evolution," as moderator Chris Matthews put it, biologist Jerry Coyne was appalled (though not necessarily surprised). As he writes in a scathing--though more in sorrow than in anger--essay, "Because there is just as much evidence for the fact of evolution as there is for the existence of atoms, anyone raising his hand must have been grossly misinformed." But while some of the hand-raising could have been the result of political calculation (more than half of Americans don't believe in Darwinian evolution, and it's always good strategy to be in sync with the majority), when Sen. Sam Brownback expanded on his hand-raising in a New York Times op-ed, the extent of his science ignorance was impossible to ignore.