This humbling and revelatory book shows how infectious disease has shaped humanity at every stage, from the first success of Homo sapiens over the equally intelligent Neanderthals to the fall of Rome and the rise of Islam. How did the Black Death lead to the birth of capitalism? Why do most North Americans speak English rather than French? And how did the Industrial Revolution lead to the birth of the welfare state? Infectious diseases are not just something that happens to us, but a part of who we are. The only reason humans don’t lay eggs is that a virus long ago inserted itself into our DNA. In fact, 8% of the human genome was put there by viruses. We have been thinking about the survival of the fittest all wrong- human evolution is not simply about our strength and intelligence, but about what viruses can and can’t use for their benefit. By confronting our ongoing battle with infectious diseases globally, Dr Jonathan Kennedy shows how germs have been responsible for some of the seismic revolutions in human history, and how the crises they precipitate offer vital opportunities to change course.