[CholeraJoe]

moved higher into the Andes as temperatures rose during the 11th century, then declined,

Gives yet another point of reference to the rising temperature in the Northern Hemisphere leading to the colonization of Greenland and later North America, occuring about the same time.

Unless, of course, you want to blame it on Incan SUVs, CFC's from the Incan's refrigerators, and llama farts.

[SunkenCiv]

[llama] "pull my hoof".