We share 98 percent of our genes with chimpanzees, yet humans are the dominant species on the planet—having founded civilizations and religions, developed intricate forms of communication, built cities, and created breathtaking works of art—while chimps are primarily concerned with the basic necessities of survival. What is it about that two percent difference in DNA that has created such a divergence between evolutionary cousins? In this book, the Pulitzer Prize-winning author of Guns, Germs, and Steel explores how the human animal developed the capacity to rule the world, and the means to destroy it.