Book excerpt: As news of war and terror dominates the headlines, scientist Malcolm Potts and veteran journalist Thomas Hayden take a step back to explain it all. In the spirit of Guns, Germs and Steel, Sex and War asks the basic questions: Why is war so fundamental to our species? And what can we do about it? Malcolm Potts explores these questions from the frontlines, as a witness to war-torn countries around the world. As a scientist and obstetrician, Potts has worked with governments and aid organizations globally, and in the trenches with women who have been raped and brutalized in the course of war. Combining their own experience with scientific findings in primatology, genetics, and anthropology, Potts and Hayden explain war's pivotal position in the human experience and how men in particular evolved under conditions that favored gang behavior, rape, and organized aggression. Drawing on these new insights, they propose a rational plan for making warfare less frequent and less brutal in the future. Anyone interested in understanding human nature, warfare, and terrorism at their most fundamental levels will find Sex and War to be an illuminating work, and one that might change the way they see the world.