yeah, know it all hair splitting tools! jerks.
Is a person to person disease older than a animal to person disease? Or did all disease start out as animal to person?
I'm taking an educated guess here, but I'd say it was all animal-to-animal originally, way back in the deep, deep pre-hominid past ca. 10 millions years ago, when we had not yet seperated ourselves from the apes.
As the various hominid species developed after the original split, they would have still had very close contact with the animal world, as they were still part of Nature themselves, not yet intelligent enough to have a 'culture' in the sense of having the idea of being seperated from the natural world, as we think of ourselves now. I could argue that it's only in the last 100-150 thousand years that anatomically and mentally modern humans--archaic and modern Homo Sapiens--have truly begun to seperate themselves from Nature and try to control their own destinies. The same could be said, at a stretch, for Homo Erectus, who were the first to leave Africa and explore the world, and for Homo Neanderthalis, who split from the ancestors of humanity some 500,000 years ago. It could be stretched even further back, to the time ca. 2.5 million years ago when Homo Habilis learned how to control fire, and thus modify their environment and begin the initial seperation from Nature as a controlling force in their lives.
So we could say that for the past 2.5 million years, about one third of our history as a species, the hominids and humans have been growing apart from Nature. I could argue that in terms of definition, disease transmission has been from animal-to-hominid or animal-to-human since then.
