Part of the meme by which so many in the "West" justify what appears to be sheer hatred for their culture and a wish for its destruction is the notion that Western culture is responsible for essentially wiping out the indigenous populations - or at least the indigenous cultures - of entire continents: Africa, North America, South America.
Yet here (ht: Maggie's Farm) is a Mexican researcher who suggests that, as bad as Cortez and the Conquistadors were, it wasn't them and the smallpox they carried which obliterated the Aztecs. It may have been repeated epidemics of a native hemoraghic disease.
From Megadeath in Mexico:
Epidemics followed the Spanish arrival in the New World, but the worst killer may have been a shadowy native—a killer that could still be out there