One new thing we know is that Amazonians were actively breeding plants at least 10,000 years ago. (The Amazon basin did not experience the Ice Ages the way temp

One new thing we know is that Amazonians were actively breeding plants at least 10,000 years ago. (The Amazon basin did not experience the Ice Ages the way temperate places did ... which is not to say nothing happened.) Five hundred years ago, the Amazon supported a population of at least tens of, and as many as a hundred, million people, mostly wiped out in a stroke by European diseases. This was a society that had time and numbers to develop deep sophistication. Did they use our scientific method? Obviously not. But that does not mean they could not have come up with their own, perhaps more-or-less equally effective and reliable system. (Ours is far from perfect; the best that can be said is that it often works.) Theirs certainly established facts ours cannot, and vice versa. Use of curare embodies a similar mystery, and ayahuasca. Certainly hundreds or thousands more secrets are forever lost. We will never know a hint of what almost all held. It is a loss easily rivalling the fabled Library of Alexandria.