For those familiar with Bad Religion vocalist Greg Graffin's life outside of music, it probably won’t surprise you to know he’s written another book. This one is called Population Wars and in it he argues that the modern day concept of “survival of the fittest” is wrong and that “life on Earth has been defined by war.” For those who aren't so familiar, the singer has a PhD from Cornell University and has lectured on evolution and life sciences at UCLA and Cornell.

Population Wars is available for pre-order now and those who head over to Kings Road to buy it can get a bundle that includes a first edition copy signed by Graffin and a one-time edition 7” featuring four acoustic Bad Religion songs recorded by the singer. The book will hit shelves on Sept. 15.

According to the band’s Facebook post, Graffin recorded acoustic versions of the Bad Religion songs that inspired him to write the new book. Those four tracks are “Faith Alone,” “The Answer,” “Past Is Dead,” and "Fields of Mars.” You can head here to grab the bundle. Population Wars is also available for pre-order on Amazon, but those who buy it that way will miss out on the 7" and the first edition signed copy.

So, what is Graffin’s new book about? Here’s a summary provided by the band, “Graffin takes the position that life on Earth has been defined by war from the beginning, with war between populations seen as an inevitable part of the evolutionary process. The popular understanding of 'the survival of the fittest,' however, is often invoked to explain and excuse many reprehensible human behaviors ... Through tales of mass extinctions, developing immune systems, human warfare, the American industrial heartland, and our degrading modern environment, Graffin demonstrates how an over-simplified idea of war, with its victorious winners and vanquished losers, prevents us from responding to the real problems we face.”

Graffin’s previous tome is called Anarchy Evolution and in it he draws connections between punk rock and other subjects like faith and evolution. Those who haven’t yet read his first book, you can order it over on Amazon.

It looks like Bad Religion fans will have plenty of summer reading to keep them occupied until the It’s Not Dead festival, where Bad Religion, Pennywise, Descendents, NOFX and more will perform. The event takes place on Oct. 10 in San Bernardino, Calif. and you can get more information and ticketing details here.

Bad Religion Talk 'True North' and Religious Views Part 1 

Bad Religion Talk 'True North' and Religious Views Part 2