In addition I'd just say read up on Latin American history in general. Slavers and missionaries worked all over the continent for centuries. It's hard to imagin

In addition I'd just say read up on Latin American history in general. Slavers and missionaries worked all over the continent for centuries. It's hard to imagine that any society survived unchanged in that environment, especially as new societies were built up. And when I say guerrilla army I'm being more figurative than literal. It seems fairly obvious there wasn't a serious power structure in place outside of the Andes, but I think that it's definitely true that the cultures we see today do not look much at all like the pre-colonial Amazonian culture.