Book excerpt: Was diabetes evolution's response to the last Ice Age? Did a deadly genetic disease help our ancestors survive the bubonic plagues of Europe? Will a visit to the tanning salon help lower your cholesterol? Why do we age? Why are some people immune to HIV? Can your genes be turned on—or off? Survival of the Sickest is fi lled with fascinating insights and cutting-edge research, presented in a way that is both accessible and utterly absorbing. This is a book about the interconnectedness of all life on earth—and especially what that means for us. Read it. You're already living it.