The Disappearance of the Anasazi—How much is really mystery?
In “The Ancient Ones: The Anasazi and Their Neighbors, “ chapter four of his book Collapse, How Societies Choose to Fail or Succeed, Jared Diamond synthesizes the archaeological research on the Southwestern US communities that flourished and then seemingly “vanished.” Diamond believes that communities need to maintain self-sufficiency in order not to collapse. He contends that when societies become dependent upon importing their needed resources, they become more vulnerable to collapse.
His thesis is that Chaco Canyon was abandoned because of BOTH the human impact on the environment and because of drought. The drought was the last straw or “proximate” cause of collapse for a society that had become overpopulated for the amount of resources it had to maintain self-sufficiency. With the increase in population due to their success at managing water and goods and developing an intricate and complex society, the society starved when drought became severe, and they had no other resources to draw upon since they had ruined the soil, deforested the region, and were dependent upon “outliers” who probably revolted to support them.
The collapse of the Anasazi communities illustrates the theme of human environmental impact and climate change intersecting, environmental and population problems spilling over into warfare, the strengths but also the dangers of complex non-self –sufficient societies dependent on imports and exports, and societies collapsing swiftly after attaining peak population numbers and power.
Diamond references a great deal of research regarding these features to help us understand how communities like Chaco Canyon were able to survive successfully for six hundred years but then suddenly fail:
Although they were a relatively small society, the Anasazi constructed in stone the largest and tallest buildings erected in North America until the Chicago steel girder skyscrapers in the 1880’s
Anasazi structures can be dated to within a year, enabling us to understand the societies’ histories pretty finely
The cultures and societies of the American Southwest are numerous (approximate dates of collapse): Mimbres (1130 AD)
Chaco Canyon, North Black Mesa, Virgin Anasazi (middle or late 12th century); Mesa Verde and the Kayenta Anaszi (1300); Mogollon (1400), and Hohokam (15th century)
They did not vanish as a people; they were incorporated in communities such as the Hopi and Zuni pueblos.
The Fundamental problem: the US Southwest is a fragile and marginal environment for agriculture, with low and unpredictable rainfall, quickly exhausted soils, and very low rates of forest regrowth. Environmental problems, especially major droughts and episodes of streambed erosion, tend to recur.
Packrat middens: a virtual time capsule of plants growing within a few dozen yards of the midden. Paleobotanists can reconstruct changes in local vegetation.
Tree rings: archaeologists can date building sites to the nearest year by the tree rings of the site’s wood construction beams.
Tree rings: because rainfall and temperature vary seasonally in the SW, tree growth rates also vary seasonally. The dry climate results in excellent preservation of wooden beams from trees felled over a thousand years ago.
Width of rings vary according to the amount of rainfall. Narrow rings means drought; wider rings indicate a wetter year, so tree rings also give us a picture of the past climate.
Origins and Agricultural Beginnings: 11,000 BC: first humans reached the Americas with colonization of the New World from Asia by peoples ancestral to Native Americans (this theory is disputed by some Native American communities). Agriculture arrived from Mexico, where corn (arrived 2000 BC), squash (800 BC), beans (later), and cotton (400 AD) were domesticated. By AD 1, Native Americans were in residence in villages in the SW, and were primarily dependent upon agriculture with ditch irrigation. Their populations exploded until the retrenchments began around 1117 AD.
Three types of agriculture emerged to cope with water management problems:
Focus on Chaco Canyon
Flourished from AD 600 until 1150-1200, deeply advanced, largest buildings in pre-Columbian North America
Today: treeless landscape, deep-cut arroyos and sparse low vegetation
Completely uninhabited except for NPS rangers’ houses
AD 600—lived in underground pit houses, like other SW Native American communities
AD 700—invented techniques of stone construction
AD 920—Pueblo Bonito: two stories, ultimately five or six stories, with 600 rooms, and logs as roof supports weighing up to 700 pounds
At first, this was an environment with advantages:
images of Pueblo Bonito
rain in 2006
Paleo slide set
Construction practices changed: the inhabitants went to mountains up to 50 miles away to haul logs, without draft animals, of ponderosa pine, spruce, and fir trees. By analyzing isotopes of strontium, researchers concluded that the Chaco Canyon Anasazi were hauling logs from Chuska Mountains and the San Mateo Mountains.
1029 AD: population still increasing in Chaco Canyon—big spurt of construction—built the Great Houses and hundreds of small settlements on the south side of the canyon. Archaeologists guess at a population around 5000-some argue more, some less.
Development and Reliance upon Outlying Communities
This population survived for awhile by relying on outlying satellite settlements—where it might rain and thus they would have a food surplus to share with the major settlement in Pueblo Bonito-- joined to Chaco Canyon by miles of roads still visible today.
Collapse: Chaco Canyon had to import its goods but it exported nothing. Imports included pottery, stone, turquoise, macaws, shell jewelry, copper bells, and food. A mini-empire resulted, with those elite living in luxury at Pueblo Bonito and outlying “peasants” much less well-fed but raising the food. We know this from studying the garbage in the various locations and the burials: the “outliers” had a higher rate of infant mortality, were more anemic, and were shorter than those people at Pueblo Bonito.
What happened? Warfare and starvation, leading to cannibalism (controversial). People were eating mice whole; evidence of cannibalism resulting from murders during war (unburied bodies, skulls with cut marks caused by scalping, skeletons were arrowheads inside the body cavity, proliferation of defensive walls, bones with smooth ends—hallmark of boiling in pots—bones cracked to extract marrow—residues of the human muscle protein myoglobin on the pots’ insides, dried human feces containing human muscle protein, normally absent from human feces)
Drought: AD 1130. Sometime between AD 1150 and 1200, Chaco Canyon was abandoned and remained empty until Navajo sheepherders reoccupied it 600 years later.
The moral of the story: we can get away with a lot of waste when times are good.
“We forget that conditions fluctuate, and we may not be able to anticipate when conditions will change. By that time, we may already have become attached to an expensive lifestyle, leaving an enforced diminished lifestyle or bankruptcy as the sole outs” ( 156)