The next great plague is out there, probably in a chimpanzee or a chicken, waiting to make the leap to humans. In his new book, Spillover: Animal Infections and the Next Human Pandemic, science writer David Quammen patrols the boundary between animal and human health, where microbial threats are emerging faster than ever
TIME: Why are we so transfixed by the threat of emerging diseases?
Quammen: Well, we know that previous big ones have been very big. There are so many humans on the planet now--7 billion of us--and we live interconnected with one another. If we're pressing ever more insistently...