Since the 1970’s, a debate has raged concerning the abandonment of the Anasazi, Hohokam, and Paquimé regions of the American Southwest and northern Mexico (a region which I call Oasis America, which is characterized by oasis and rivers in a desert environment). Drought, famine, erosion, deforestation, salinity, soil infertility, warfare, cannibalism, and general resource depletion have all been proposed as causes for the desertion. For the most part, these reasons have been found not to be a primary cause of abandonment. I concur, after thoroughly researching each of these issues, that all of these “causes,” taken together, very likely contributed to the severe dietary stress of the Anasazi/Hohokam/Paquimé cultures but were not the primary causes.
In a related debate, Marvin Harris proposed that a lack of “red meat” might have been a causation. He argued that a simple diet of corn and beans was not adequate to support complex, high-density cultures. Later, Louis E. Grivetti demonstrated that corn and beans did provide the adequate essential amino acids necessary for basic nutrition in pre-Columbian North America but does not address the general health of the population required for large building projects such as Pueblo Bonito at Chaco Canyon utilizing these very limited dietary resources.
I observe that a very specific lack of dietary iron was the ultimate root cause of the abandonment. I further propose that this might also be interpreted as the cause of the scientifically validated cannibalism in the Anasazi areas (Turner and others). It is widely accepted by archaeologists and anthropologists that pre-Columbian North Americans, in fact, had very few domestic animals. Harris correctly points out that these domestic animals competed with humans for the basic foods: corn, beans, and wild red meat. The lack of red meat and animal fats, due to the severe depletion of locally available wildlife, was a significant challenge to complex, high-density cultures such as that at Chaco Canyon. I agree, as well, with Grivetti that corn and beans would have provided the essential amino acids but the evidence demonstrates they could not provide the absolutely necessary dietary iron.
I propose that it was the essential lack of dietary iron that presented the Anasazi with a final and insurmountable obstacle to high-density, complex culture without resorting to cannibalism. I further observe that some groups of the Anasazi and others resorted to cannibalism (as did the Aztecs), but this practice was rejected by the majority of the population. It is noted from the following paper that Chaco Canyon has the highest rate of anemia when compared to the other Anasazi sites. Considering the bone evidence for the very poor nutritional status at Chaco Canyon, it is surprising that the Chacoans were able to accomplish any vigorous tasks at all. This contradiction highlights the very poor understanding of Chaco Canyon agriculture and life-styles currently. My proposals provide the key for pursuing the resolution of this mystery.
Health and Disease in the Prehistoric Southwest a summary of key writings on Anemia - “Mesa Verde has yielded an abundant amount of skeletal remains (500 or so) from numerous excavated sites dating from 600 B.C. to A.D. 1300. Most of the remains are from the later time periods (A.D. 1000-1300) ... a low life expectancy as indications of a stressed population.
According to Akins, Chaco Canyon Anasazi suffered from what she terms “subsistence stress” as indicated by growth disruption, high rates of nutritional anemia, and degenerative diseases (1986:135). ...
|“authority-holding elites had greater access to nutritional resources and enjoyed better health (1986:137-140).
Bone density in adult males and females is the lowest during the abandonment phase, which probably reflects poor overall nutritional quality at that time. ... In addition to studies on the Mesa Verde and Chaco burials, human skeletal remains from the Kayenta region have also been analyzed. .. Similar to previous studies, Wade suggests that health was poor, with a slight trend toward increased stress in the later time period.
Ryan (1977) used Wade’s Puerco Valley sample but combined it with burials from several other Kayenta Anasazi sites (A.D. 750-1300) and one historic Hopi site (Old Walpi, A.D. 1300-1700). His sample consisted of 353 burials representing Pueblo II through Pueblo IV occupation. ... Ryan suggests that health status dramatically decreased during the final stages of occupation. ... the study by Palkovich (1980) of 120 burials from Arroyo Hondo, located in central New Mexico in the Rio Grande area. This enormous site was occupied during two separate periods referred to as Component I (A.D. 1300-1330) and Component II (A.D. 1370-1420). Each occupation shows growth, prosperity, and sudden decline. ... Palkovich paints a harsh picture of the Arroyo Hondo Anasazi. Most individuals were afflicted with some pathology, and infant mortality was very high. Of the 54 subadults aged to 10 years, she further documents a very high rate of active infections and anemia in infants under the age of one (Palkovich 1987). ... Palkovich speculates that Arroyo Hondo infants have immediately acquired infections from their mothers, implying that maternal health was greatly compromised during pregnancy.
the study of Arroyo Hondo ethnobotanical reconstruction of food and diet, suggests strongly the presence of endemic malnutrition. ...
One common finding almost all the paleopathological studies reviewed here is the presence of nutritional anemia. El-Najjar and colleagues (1976) compared numerous Southwest skeletal populations based on dependency on maize (which is assumed to be a poor source of iron, protein, and other nutrients). Their sample was drawn primarily from Chaco and Kayenta sites, and they divide them into two ecological types: canyon bottom sites (maize-dependent subsistence) and sage plains sites (mixed maize subsistence). The study documents much higher frequencies of nutritional anemia in the canyon bottom sites and concludes that maize dependence in marginal areas such as those found in the Southwest predisposes individuals, particularly children, to health problems. ... Walker expanded this finding with an exhaustive review and synthesis of the published literature on anemia from all major Southwestern sites. ...
”The remarkable prevalence of osseous lesions indicative of anemia among prehistoric Southwest Indians apparently resulted from the interaction of a complex set of biological and cultural variables relating to nutrition and infectious disease. Lack of iron in the diet, prolonged breast feeding, diarrheal and helminth infections, and living conditions conducive to the spread of disease all appear to have contributed to the prevalence of [anemia] [1985-153].”
characterize health in the following manner: major nutritional deficiencies resulted from a corn diet ... major concern; most adults had arthritis and spinal degeneration from carrying heavy loads; parasites such as lice and helminths were common; and infant and childhood mortality was high.