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January 14, 2012

The old Amazon

Filed under: Agriculture,Amazon,Anthroplogy,Charles C. Mann,Environment — Razib Khan @ 2:49 pm

Once Hidden by Forest, Carvings in Land Attest to Amazon’s Lost World:

For some scholars of human history in Amazonia, the geoglyphs in the Brazilian state of Acre and other archaeological sites suggest that the forests of the western Amazon, previously considered uninhabitable for sophisticated societies partly because of the quality of their soils, may not have been as “Edenic” as some environmentalists contend.

Instead of being pristine forests, barely inhabited by people, parts of the Amazon may have been home for centuries to large populations numbering well into the thousands and living in dozens of towns connected by road networks, explains the American writer Charles C. Mann. In fact, according to Mr. Mann, the British explorer Percy Fawcett vanished on his 1925 quest to find the lost “City of Z” in the Xingu, one area with such urban settlements.

In addition to parts of the Amazon being “much more thickly populated than previously thought,” Mr. Mann, the author of “1491,” a groundbreaking book about the Americas before the arrival of Columbus, said, “these people purposefully modified their environment in long-lasting ways.”

If one wants to recreate pre-Columbian Amazonia, most of the forest needs to be removed, with many people and a managed, highly productive landscape replacing it,” said William Woods, a geographer at the University of Kansas who is part of a team studying the Acre geoglyphs.

“I know that this will not sit well with ardent environmentalists,” Mr. Woods said, “but what else can one say?”

There are two descriptive models which have to be interpreted in different normative frames. First, there is the model whereby before the arrival of the Europeans the New World was lightly populated by indigenous groups which had a minimal impact upon the environment. This is the description. Before the 1960s this was viewed by the mainstream culture as a rationale for the justified conquest of the New World by Europeans, who put the land to productive economic usage, whereas before it had been fallow and under-untilized. After the 1960s many, especially in the environmental movement, inverted the moral valence of the description. Instead of being primitive savages, the native peoples were at balance with the environment. Rather than an outmoded way of life to be superseded, they were a potential model for the future.

The second descriptive model is the one that Charles C. Mann outlines in 1491: New Revelations of the Americas Before Columbus. It posits that in fact the New World was much more heavily populated and its environment more impacted by humanity than we had thought previously. Rather, it suggests that the introduction of Old World diseases resulted in massive population crashes, subsequent to which there was a “re-wilding” of much of the Americas. Mann focuses more on the period before the arrival of Europeans, but if you read the scholarship on the arrival of Paleo-Indians there is a fair amount of evidence that even their appearance resulted in a massive change in the suite of fauna which characterized the New World (e.g., the gray wolf and American bison are also Holocene newcomers, just like man).

Some have argued tat Mann has taken a maximalist position (in fact, some readers have lied and stated that Mann argued that the Amazon was as populated as Bangladesh!). But even granting that Mann may be sampling from the more revisionist tail of the scholarship, I think it is creditable that we need to move away from the extreme position of the first descriptive model. There is a fair amount of circumstantial evidence that New World civilizations had not attained the same level of sophistication and complexity as Old World civilizations (see Guns, Germs, and Steel for some of the reasons why). But it is also likely that the Aztecs and Incas were not sui generis aberrations, but rather one point along the spectrum of social complexity which characterized the New World.

This is a subtle point though, because the new model also has normative ramifications. I state above that New World civilizations were not as complex or developed as Old World ones, and that is not a position that many are comfortable with. Rather, they may want to assert that the New World societies were just as complex and sophisticated as the Old World civilizations, that fundamentally all civilizations have equal value and similar character. Therefore, these partisans are particularly enthusiastic about the model which Charles C. Mann popularizes in 1491, as it reverses the narrative of noble simple savages, projecting the indigenous as highly cultured, and only brought down by the biological weapons which Europeans brought.

Where does that put those who wish to construct a plausible model of reality, rather than a mythic history for purposes of ideology? It is lazy to simply pick the position in the middle, but in this case that’s probably the most prudent unless you want to dive into the primary literature yourself. I don’t accept the old model anymore for a variety of reasons, not just having to do with the natural history of the New World. But, I can’t personally assess in detail the magnitude of the numbers that some of the scholars Mann relies upon to revise upward population estimates. So I take the revision with a grain of salt and some caution.

I would conclude that there is one reason I can think of why the Amazon basin might have been more suitable for human habitation that some other wet tropical zones in the Old World: the relative lack of disease. Many wet lowland zones which would otherwise be suitable farmland are lightly populated due to malaria, but this was not an issue in the New World before 1492.

January 2, 2012

Our symbionts are death!

Several readers have expressed skepticism of the high mortality numbers Charles C. Mann reports in his two books in relation to the Columbian Exchange. In case you are not aware, the thesis that Mann outlines is that the primary necessary condition whereby Europeans managed to eliminate indigenous populations from much of the New World was that they brought with them diseases which the native people did not have an immunity to. This model often argues that mortality rates were on the order of 90 percent. Such a scenario has broad plausibility because the situation in the New World has an inverse counterpoint: Africa.  Before quinine the European dominion on the continent was limited to outposts and fringes (e.g., the Cape region of South Africa, which was free of many of the diseases deadly to Europeans). Overall I find Mann’s argument qualitatively reasonable, even if one may qualify it on the margins quantitatively. But I stumbled upon more evidence recently: it still holds for those Amerindians which have not been exposed to Eurasian diseases. From a National Geographic story, Into the Amazon:

But violent clashes account for only a fraction of the deaths suffered by native communities at the hands of outsiders. Most died from epidemic diseases, including the common cold, for which they had no biological defenses. Ivan Arapa, one of our scouts, is from the Matis tribe, who were first contacted by the outside world about 25 years ago. Ivan still remembers the wholesale death that accompanied these very first visits of Brazilian government officials to his village.

“Everyone was coughing, everyone was dying,” he recalls. “Many, many Matis died. We didn’t know why.”

More than half of the 350 Matis living along the Ituí River inside the Javari reserve perished in the months following contact, officials say.

It’s a dismal story that’s become all too familiar to Possuelo during his 40-year career as a sertanista, a uniquely Brazilian profession that folds all the skills and passions of a frontiersman, ethnographer, adventurer, and Indian rights activist into a single, eclectic vocation. That’s why our mission is not to make contact with the Flecheiros but rather to gather information on the extent of their territory’s boundaries, information Possuelo will use to bolster his efforts to protect their lands. In other respects, the Flecheiros are to remain, in large measure, a mystery.

Over thousands of years Eurasians, and to a large extent most inhabitants of the “World Island” (Eurasia + Africa), have become habituated to a range of endemic ailments which may make us miserable, but do not kill us. Our bodies are hosts to an order of magnitude more bacteria than our own tissue cells. Most are innocuous or beneficial, but some are potentially deadly. Many of us carry pathogens which do not result in any illness over our lifetimes. There are geneticists who argue that a small minority of people exhibit genetic susceptibilities to pathogens which are normally benign. What if these people are the ancestral type?

I think about this in particular when considering the case of the Sentinel Islanders. This tribe has been left alone by the Indian government, and remains out of contact with the rest of humanity. Some of this is a function that other Andaman Island tribes which have had extensive contact with people from the mainland have not done so well due to the combined effects of Indian disease and diet. But is it right and proper that modern humans be isolated from the rest of the population for their own good? What does the reality of a whole people who are viewed as “Bubble Boys” tell us about the range of the human condition?

September 2, 2011

10 Questions for Charles C. Mann

Filed under: Charles C. Mann,History — Razib Khan @ 9:42 am

Over at Discover Blogs. Mostly about 1493: Uncovering the New World Columbus Created.

September 1, 2011

10 Questions for Charles C. Mann

Filed under: 1491,1493,Anthroplogy,Charles C. Mann — Razib Khan @ 11:02 pm
Charles C. Mann is the author of several books, including 1491: New Revelations of the Americas Before Columbus and 1493: Uncovering the New World Columbus Created. Much of his work has been involved in publicizing the ecological factors which shape the course of human history. You can read a lengthy review of 1493 over at [...]

May 22, 2011

1493: Uncovering the New World Columbus Created

For obvious reasons I don’t usually post about material I haven’t read, but Tyler Cowen points me to the fact that Charles C. Mann has a new book coming out this summer. If you haven’t, I would highly recommend his previous book, 1491: New Revelations of the Americas Before Columbus. I think it is correct that Mann probably skewed his narrative a bit too much to the revisionist side, but it is a genuinely revelatory work.* I was aware of the broad outlines already, so it wasn’t surprising, but he marshals the data in a fascinating and engaging manner. The new book is apparently a sequel of sorts, 1493: Uncovering the New World Columbus Created. Cowen says “I am spellbound reading it, it will be one of the best books of this year, and, although I know this area somewhat, I am learning fascinating information on literally every page.” I suspect that what occurred in the New World after 1492 is actually an amplified version of what occurred across much of the Old World over the past 10,000 years, with the rise of massive agglomerations of ...

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