From the very beginning, life on Earth has been defined by war. Today, those first wars continue to be fought around and literally inside us, influencing our individual behavior and that of civilization as a whole. War between populations-whether between different species or between rival groups of humans-is seen as an inevitable part of the evolutionary process. The popular concept of "the survival of the fittest" explains and often excuses these actions. In Population Wars, Greg Graffin points to where the mainstream view of evolutionary theory has led us astray. That misunderstanding has allowed us to justify wars on every level, whether against bacterial colonies or human societies, even when other, less violent solutions may be available. 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. Along the way, Graffin reveals a paradox: when we challenge conventional definitions of war, we are left with a new problem, how to define ourselves.