Comments by "John Roberts" (@view1st) on "History Buffs" channel.

With regards the universally held idea that smallpox originated in Europe and then spread like wildfire through the native population, decimating it, I have heard a theory that smallpox in fact was already present in at least some of the native population of the Americas, albeit in a considerably less virulent form with many people contracting it during childhood. In fact it was this prior contact with the disease that granted them a degree of immunity such that the European version had to evolve to become super virulent just to survive (Europeans being somewhat resistant to this, their own version of smallpox). Don't know how true the theory is though.
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