In the battle between creationism and evolution in American schools, Louisiana is on the front line.
In 2008, it became the first state to pass controversial legislation allowing schools to stop teaching evolution in science lessons and instead focus on the "controversy" of the conflict between Darwinism and creationism. Since then, a similar bill has been passed in Tennessee and more are proposed for eight other states.
Two years after the new curriculum was approved in Louisiana, a student at Baton Rouge Magnet High School made it his final-year project to get the bill repealed. Zack Kopplin (pictured right) won support from Nobel prizewinning chemist Sir Harold Kroto, but attempts to get the bill overturned were voted down.
After a third repeal attempt narrowly failed earlier this month, Mr Kopplin, now 19, has put his college studies on hold for a year to work full-time on a new campaign: the Second Giant Leap for Humankind, which opposes anti-science legislation and is calling for a trillion-dollar, decade-long investment in science education.
Speaking to TES, Mr Kopplin shrugged off the latest setback, saying that the momentum is with the repeal movement. "We will repeal this law, one way or another. It will happen, maybe not this year, but next year or the year after," he said. "There's a chance to be on the right side of history or the wrong side of history."
The first repeal bill was rejected by the Louisiana State Senate Education Committee by five votes to one. In the second, the vote went two to one against, with most abstaining. This time, the committee voted three to two against.
"We are making progress. We are wearing them down; each year the votes get more close," Mr Kopplin said. "They're getting more worried about us."
This year, the Discovery Institute, a pro-intelligent design thinktank based in Seattle, Washington, which created the model legislation used by Louisiana, felt the need to send a lobbyist.
Even the most liberal countries are not immune from clashes over evolution: in 2005, a Dutch education minister drew criticism from scientists for proposing the teaching of intelligent design to encourage debate between different religions.
In the UK, the rise of free schools, which can be set up by teachers, parents or charities and are exempt from following the national curriculum, has attracted interest from creationist groups. And members of the Discovery Institute have targeted UK schools, sending anti-Darwinist textbooks to their libraries.
But nowhere is the conflict as intense as it is in the US. And, according to Mr Kopplin, Louisiana is "ground zero" for the battle between creationism and science.
The legislation Mr Kopplin is opposing, the Louisiana Science Education Act, allows teachers to use supplemental materials that contradict established science, on the grounds that this encourages critical thinking.
"Bottom line, at the end of the day, we want our kids to be exposed to the best facts: let's teach them about the Big Bang theory, let's teach them about evolution," Louisiana governor Bobby Jindal told the television network NBC in a recent interview. "I've got no problem if a school board, a local school board, says, `we want to teach people about creationism'. Some people have these beliefs as well - let's teach them about intelligent design."
Mr Kopplin said that no one knows how many schools are using creationist materials and that the act has been designed in a way that makes it difficult to audit.
Some school boards have responded to the act by expressing their support for creationism. In 2010, Livingston Parish school board member David Tate said: "We let them teach evolution to our children, but I think all of us sitting up here on this school board believe in creationism. Why can't we get someone with religious beliefs to teach creationism?"
But others have made their opposition clear: last year the Orleans Parish School Board received hundreds of messages of support after it voted to ban any science textbook "which presents creationism or intelligent design as science or scientific theories".
Mr Kopplin said that senators who voted for the act feared that conservative groups would back rival candidates in primary elections if they did not support the law.
"There are enough people on the committee who know evolution is right," he said. "But we have to advocate against powerful groups such as the Louisiana Family Forum, the group recognised as getting the law passed and the most powerful lobbying group in Louisiana. It's the one group that wants the law."
The latest repeal attempt was supported by one Democratic and one Republican senator. The other Democratic senator opposed the repeal, explaining that he had been cured by a spiritual healer and feared that repealing the act could "lock the door on being able to view ideas from many places, concepts from many cultures".
"If I closed my mind when I saw this man - in the dust, throwing some bones on the ground, semi-clothed - if I had closed him off and just said, `That's not science. I'm not going to see this doctor,' I would have shut off a very good experience for myself," he told the committee.