[pepsi_junkie]

Note that the diseases on your chart only go in one direction, from Europe to America. Why? I recall a looong time ago (1980s probably) in Discover Magazine Jared Diamond wrote an article called “The Arrow of Disease” that asked that question but I don’t recall what his conclusions were. Still, the question has stuck with me.

[Daffynition]

Gee that was hard to find.

Grab some intellectual honesty on the way out.

http://discovermagazine.com/1992/oct/thearrowofdiseas137

[Harmless Teddy Bear]

Most human diseases come from living with animals. Horses, chickens and especially pigs being the main ones. Since in the Americas there were only a few domestic animals they neither developed those diseases or developed immunity to them.

Which is probably a good thing as if diseases had hit Europe as hard as they did the Americas we would be speaking Arabic or Chinese now.