I probably know less than you, but I do know that the potato was domesticated by the Incas and that they had no written language that anyone knows of, although I read a good article in Smithsonian about a system of strings and knots that may be a tangible production of storytelling and record keeping. In an excellent book Guns, Germs and Steel, there is a brutal first-hand account of a first Spaniard-Inca encounter--brutal.