We have an idea of where to place the cradle of civilization, but where is the cradle of disease?
Where do infectious diseases come from? Some come from animals, but we gave some back (as cattle picked up TB from farmers). Leviticus discusses the problem of leprosy at some length and even develops an early form of quarantine. Epidemics of various kinds began only when human populations and the first cities (Babylon included) were large enough to sustain the infectious agents responsible.
Now genetics, of humans and their enemies, is beginning to tell us more. And the news is not good.