Wisconsin Gov. Scott Walker delivers his speech at Chatham House in central London. (Lefteris Pitarakis/AP)

Wisconsin Gov. Scott Walker probably wasn’t expecting a science quiz while he was on a trade-related trip in the United Kingdom. But when you’re considering seeking your party’s nomination for president, you can’t rule out any questions.

At a question-and-answer session in London, after Walker had already dodged other, non-science questions, he was asked whether he accepts evolution. His response: “I’m going to punt on that one as well.”

In recent years, Republicans in particular have sought to dodge questions about their views on climate change by responding, “I’m not a scientist.” In some ways, this sort of response reflects the tricky politics that Republicans in particular face: balancing the views of conservative base voters with the need not to alienate independents and moderates.

The other part of Walker’s response, however, raises even more eyebrows: “That’s a question that a politician shouldn’t be involved in one way or another.” Essentially, Walker was arguing that one’s stance on evolution is akin to a personal belief that has no relevance to a politician’s duties.

But today, a day after the 206th anniversary of Charles Darwin’s birth, here’s why Walker is wrong about that — with a look at a similar incident from the 2008 presidential nomination process.

Science and the presidency

In one of the GOP presidential debates in 2007, candidates were asked whether they accepted or rejected evolution. In response, three of the 10 candidates on stage responded that they didn’t accept evolution, including former Arkansas governor Mike Huckabee. And when Huckabee later appeared on “Real Time with Bill Maher,” Maher asked Huckabee to clarify his statements.

Huckabee not only doubled down on his stance, he did what Walker did the other day. “I thought the question was utterly silly to be asked in a presidential debate,” Huckabee responded. “None of us are running in order to be an eighth-grade science teacher. We’re running to be president.”

To which Maher retorted: “Why shouldn’t I take that into account when I’m assessing the rationality of someone I’m going to put into the highest office in the land?”

To be fair, Maher himself is not a paragon of scientific excellence, given some of his views on medicine. But the broader point Maher raised is apropos: Politicians’ views on certain matters that are seemingly personal are important to their jobs. And this couldn’t be more true with science.

Some of society’s most pressing issues, such as climate change, are highly technical, and science is crucial to understanding why they’re problems to begin with. There’s a reason that the United Nations’ Intergovernmental Panel on Climate Change includes a “summary for policymakers” with its scientific assessment reports, and why public health agencies employ teams of epidemiologists.

How science and policy are linked

But that’s not all. We can use what science tells us to find ways to improve society and solve those societal problems — not just through the development of technologies or medicines, but through public policy.

And government agencies do this all the time. The Environmental Protection Agency (EPA) draws on the work of toxicologists and epidemiologists to formulate its regulations for toxic chemicals and pesticides. The U.S. and other global governments might draw on global warming projections from the IPCC in figuring out what emissions cuts are needed to stave off a certain amount of warming.

The Centers for Disease Control and Prevention’s response (and that of the broader global health community) to the Ebola crisis, meanwhile, was shaky, at least at first. But if science hadn’t told us about how the Ebola virus spreads, how the virus works, and how diseases spread in populations more generally, things might have turned out much worse.

The way politicians view science, then, is hardly a personal matter. It’s a signal for the kinds of knowledge they find most valuable and, potentially, would use to inform their policy platforms or decision-making.

After the initial media attention that Walker received, he sought to clarify his remarks on Twitter:

Many religious people have found ways to reconcile their religious beliefs with acceptance of evolution — a prominent example being Kenneth Miller, a Brown University biologist who both champions the teaching of evolution in public schools and is a devout Catholic. But Walker’s clarification doesn’t actually clarify his stance on evolution. Instead, it further muddies his initial nonresponse.

On the one hand, you can sympathize with Walker, as evolution isn’t the first thing you’d expect to get a question about during a trade-related event. And the politics here are tricky: Evangelicals and conservative Christians, many of whom polling suggests reject evolution, make up a sizable portion of the Republican Party’s base. It should come as little surprise, then, that a plurality of Republicans believe that humans have always existed in their present form. Many Democrats and independents (albeit fewer) hold this view, too.

On the other hand, any politicians seriously considering running for the presidency can and will face questions over matters that aren’t directly on the day’s agenda, including science. And the media won’t make exceptions for tricky political situations. Other potential presidential hopefuls have learned that same lesson recently when it comes to vaccines, including Sen. Rand Paul (R-Ky.) and New Jersey Gov. Chris Christie (R). And this shouldn’t even be a partisan matter — rejection of key areas of science can and does occur on both sides of the aisle.

If there’s a broader lesson here, then, it’s that science can be, will be, and should be on the table (and at least one organization is pushing to make that happen in 2016). It’s not just a matter of personal viewpoints. It’s a matter of policy.