For thirty years Greg Graffin has fronted the punk rock band Bad Religion, which revolutionized the genre and paved the way for the likes of Green Day with its intricate harmonies and thought-provoking lyrics. But in his spare time, Graffin—who received a doctorate from Cornell and a lifetime achievement award from the Harvard Secular Society—teaches evolutionary biology at UCLA and scrutinizes the mysteries of the fossil record. (Not exactly Sid Vicious, this guy.) His band's fifteenth album, The Dissent of Man, and his first book, Anarchy Evolution: Faith, Science, and Bad Religion in a World Without God, were both released on September 28.

You've criticized theism for three decades, but ultimately found contentment through naturalism. How is this different than "spiritual but not religious"?
I call myself a naturalist as opposed to an atheist, but there are different styles. Some people just like to be close to nature. And some people actually worship nature, which is too wishy-washy because—like a lot of religious believers—they don't depend on facts. I have great hope and faith, but it's a humanistic faith based in facts; you have to believe that facts exist. We can all arrive at the same facts if we engage in the process of experimentation, observation, and verification, which can solve more of the world's major problems than a debate over whether God does or doesn't exist.

Do you feel it's an improvement that many theists are backing away from Young Earth creationism, and instead viewing evolution as a divinely ordained process?
It's an improvement, but it would be a huge improvement if you take God out of the question entirely. Let's not worry about Aristotle's first cause; let's focus millions of people toward improvements in medicine, not why your argument is sounder than someone else's for who or what started it all. It's the same with the "four horsemen" [Richard Dawkins, Daniel Dennett, Sam Harris, and Christopher Hitchens], who do caustic better than I can, but it's much more useful to discuss the laws and working of nature than to discuss atheism. People only have so much attention to give to this subject.

You've compared some scientists to religious fundamentalists before.
I've always had a problem with authority. The authorities in vertebrate evolution assumed that the ancestor of all vertebrate came from marine organisms. I did field work in the Sangre de Cristo Mountains, and found ample evidence in the sediment—which contained early jawless fishes, some of the oldest fragments known—for signatures of freshwater deposits, [which suggest that the earliest vertebrates originated in freshwater streams and rivers]. I tried to publish an article about my conclusions, but that was one of my first forays into recognizing how difficult it is to present data contrary to the commonly held opinion. The first round of reviewers at Science liked it, but the second round just refused to consider the alternative I was presenting. It was widely ignored until Philippe Janvier cited my paper in the definitive book on early vertebrates.

I'd love to do more field work, but this damn rock 'n' roll business keeps me away from it. (Laughs.)