A new paper, Evidence for mid-Holocene rice domestication in the Americas, suggests that the Amazon basin was very culturally productive in the pre-Columbian period. What happened? From the conclusion:
The arrival of Europeans to the American continent in AD 1492, with the consequent population decimation and impact on cultural practices, caused the domesticated traits to gradually disappear. The loss of domesticated varieties is a phenomena that has also occurred for other indigenously domesticated species in both South….
One of the novel arguments in Charles C. Mann’s 1491 is that our idea that the Amazon basin has always been a pristine wilderness could be incorrect. Mann relays the theories of revisionist scholars who argue that at one point in history much of the basin was subject human landscape manipulation, with concentrated burnings allowing for increased productivity in the normally poor soil of the region. Of course, this triggered a counterattack from classical scholars.
If these results about rice domestication are confirmed and become solid I think this would lean toward supporting the arguments of the revisionists, whose side Mann seems to favor in any case.
A major general theme in 1491 is that the Columbian Exchange was a disaster for New World peoples, though relatively positive for the Old World. European access to land surplus in the New World has been given as one reason for the economic takeoff of this region (“ghost acres”), while maize introduced into China was responsible for its great population expansion in the centuries leading up to 1800.
In contrast, the consensus seems to be that New World populations suffered massive population declines (some of this has been confirmed by genetic evidence) driven in large part, though not exclusively, by introduced Old World diseases. Mann argues that early fantastical reports of a dense network of villages along the Amazon (which may have fueled legends of El Dorado) actually reflect the reality that in the 16th century the riverine civilization had not collapsed due to disease. At least not yet.
Let’s stipulate that rice domestication in the Amazon was occurring before 1492. This adds another independent domestication event during the Holocene. Basically, agriculture seems to be something that pops up over and over again after the end of the last Ice Age. Why? As I have suggested before a lot had changed since the previous interglacial over 100,000 years before the present. Our cognitive orientation and our cultural toolkit seem to evoke agriculture relatively quickly and independently.
Second, the indigenous peoples of the Amazon today are predominantly hunters and gatherers or slash & burn agriculturalists. Relatively simple societies. In 1491 the author outlines that that mass death often resulted not directly from disease, but the fact that the debilitation of large proportions of the population then led to famine, which led to social disruption and institutional collapse, which then fed into more death and destruction. Today we perceive the Amazonians as “ancient” and “primal” nomads of the forest, just as their tropical homeland is seen to be eternal and everlasting. This, despite the fact that many of them even today are agriculturalists, albeit of a low-intensity sort. But as they are, perhaps so we could be. Complex societies seem to unravel awful quickly when subject to exogenous “shocks.” Perhaps we should be grateful for our “Pleistocene minds.” You never know when a swiss-army-knife mind is going to come in handy….
Note: the natives of the Amazon are unique in the Americans is having a very basal Asian ancestry in their heritage.