Wisconsin Gov. Scott Walker declined to answer a question about whether he believes in evolution during an appearance in London on Wednesday.

Walker, a Republican who's mulling a presidential bid in 2016 and has seen his stock rise in recent weeks, was traveling in London as part of a trade mission to promote business ties between his state and the United Kingdom. The sole public event during his foreign foray was a speech at the Chatham House in London.

During a question-and-answer session after his speech, Walker was asked whether he's comfortable with the idea of evolution by natural selection and whether he believes in it personally.

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"I'm going to punt on that one as well," Walker replied. "That's a question a politician shouldn't be involved in one way or the other."

The question, though, isn't merely a matter of scientific curiosity. Many Christian conservatives object to the teaching of Darwinian evolution in public schools, and they've made some progress in recent years in pushing curriculum that frames evolution as just one of many theories about the origin and progression of life.

Because education policymaking is done primarily at the state level, a number of governors have weighed in on the issue, and several state legislatures have debated bills that would permit public schools to teach alternative theories like intelligent design, which holds that life was created by some kind of higher power.

Walker signaled Wednesday that he's not exactly leaping to opine on the issue, perhaps mindful that a definitive answer could put him at odds with either swing voters or a segment of conservative voters.

Walker later added on Twitter, "Both science & my faith dictate my belief that we are created by God. I believe faith & science are compatible, & go hand in hand."