His thesis is that the American Indians were here longer than thought, and had made greater changes to the land and built greater civilizations than the usual histories allow for; that what the later colonists found was often the residuum of a collapsed culture.
Reading about some of the earlier collapses (e.g. the Maya) got me wondering if the African rain forest holds monuments from similarly forgotten collapses. They'd have to be earthworks: stone would have been discovered already and wood vanishes very quickly. I wonder how cheap it is to do remote sensing of the jungle floor. I have a stone sculpture of a type Liberians sometimes find in the fields: they have no idea who made them.
I gather people have been experimenting with teosinte since 1896: has anybody tried a full-fledged replication program? They claim modern breeders could get a proto-maize in 10 years; I'd love to see them try. Granted, it would cost a bit. But the practice would be useful: next they could try with some other old crops, to get easily harvestable yields from something like maygrass.
One of the key claims in the book is that disease destroyed up to 90% of the Indian population in a few years. De Soto and LaSalle might have been traveling through different lands if you just go by the description of the people. That rate seems pretty high: dang few diseases have mortality rates that large. If one disease after another rolls over an area you could do it, but the toll from the first one would reduce the contact rate and the spread of subsequent diseases. But maybe...
The claim that part of the Amazon was planted as an orchard is interesting. The devil is in the details though. Do the trees ripen at different enough times, and can storage be reliable enough in a rain forest, to sustain people all year round? I've lived in a rain forest, and pests are ... well ... serious pests.
Fire, fire, fire. Poor Smokey the Bear. Whether by calculation or convergence on a working strategy, North American Indians seem to have kept the landscape smoking a lot. And in the Amazon too, which of course puts environmentalists in a bind: do we preserve the habitat as it is, or as it was, or in some wild guess as what it would have been if there'd never been any people?
I'm a little vague on what happened between the era he describes in the 17'th century with Indians and colonists living nearby, and later observations where the most common description of Indians is "drunken." Possibly the colonists had already set up a society that demanded a revenue stream, and people outside the system couldn't maintain property. I dunno. Family tradition says that Grandpa's house in Mississippi (a haphazard telescope house) contains as its oldest portion the home of an Indian; and if so the Indian in question had fairly decent housing for the time. (Don't ask; Katrina did a number on it.)
If you haven't read it yet, do. I ordered 1493. And somehow I have to see if I can find hickory milk...