Thomas H. Wilson
Cultures rise and fall. The collapse of civilization is as captivating as its rise. Where are the ancient Egyptians, Assyrians, Romans and Greeks? What happened to the great caliphates and the ancient civilizations of Peru? Historians, archaeologists and other scholars study the decline and fall of civilizations as avidly as their rise. Are there circumstances and pressures shared by civilizations in decline? If so, how and to what extent are they relevant to us today? Does study of the collapse of civilizations suggest ways that we might avoid it? Do we ignore the reasons of collapse at our peril?
I have worked in three areas where abandonment of sites and regions or full cultural collapse occurred: the ancestral pueblo and Hohokam areas of the American Southwest, the ancient Maya of Mexico and Central America, and the Swahili of the coast of eastern Africa. Each of these sheds light on the causes and mechanisms of collapse and perhaps provides clues to avoid a similar fate.
Pueblo Bonito, Chaco Culture National Historic Park, San Juan Basin, northwestern New Mexico. Intense drought beginning about 1130 on the Colorado Plateau caused construction at Chaco Canyon to cease and depopulationby 1180.
My earliest work as an archaeologist was in the ancestral pueblo areas of the American Southwest. Puebloan peoples today inhabit the Hopi mesas in Arizona and the Zuni area and the Rio Grande Valley in New Mexico. Previously, peoples in the ancestral puebloan traditions lived in the Four Corners region of the Colorado Plateau and adjacent areas, such as at Mesa Verde and Chaco Canyon. Chaco Canyon suffered drought beginning in 1130 and its inhabitants left by about 1200. Severe drought visited the San Juan and Little Colorado River drainages 1276-1299. The puebloan peoples abandoned Mesa Verde and hundreds of other sites, and the region was largely uninhabited by 1300. In the Sonoran Desert areas of Arizona and along the Salt and middle Gila Rivers, the Hohokam civilization, based upon major irrigation networks, flourished contemporaneously with the prehistoric pueblos. The Hohokam experienced great population growth between about 1100 and 1300, which made use of all available water and stressed their irrigation system. Between about 1400-1450 the Hohokam ceased canal building and abandoned their great sites such as Pueblo Grande, Mesa Grande, Casa Grande and many more.
Keet Seel, Navajo National Monument, northeastern Arizona. Keet Seel was inhabited about 1250, construction ceased about 1286, and the cliff dwelling was abandoned shortly thereafter.
What happened? Short-term severe climate fluctuation was a factor as the dates suggest, but the problems the pueblo and Hohokam peoples experienced were much more complex than single factor explanations. Archaeologists cite competition for or depletion of resources, failure of water control systems, warfare, stressed social systems, population aggregation, interrupted trade networks, disease, and other factors to explain the abandonment of these prehistoric cultural areas.
Temple I and the Central Acropolis from the North Acropolis at Tikal. The pyramid is the funerary monument to Jasaw Chan K’awil, who was buried in 734. The final monumental inscription at Tikal was 10.2.0.0.0, A.D. 869.
Ancient Maya civilization arose in northern Guatemala, southern Mexico and western Honduras beginning around 1500 BCE. In the beginning, these were small farming communities raising maize, beans and squash and collecting from wild animal and plant communities. Well before A.D. 300, the Maya were developing the elements that would define ancient Maya civilization: monumental architecture, dated inscriptions with historical information carved on stele, and polychrome ceramic traditions. Maya leaders or “kings” arose from prominent lineages and reinforced their authority through ritual and arms. The inscriptions tell us that intercity warfare and conquest were characteristic of ancient Maya society. For over 600 years, from 300-900, Classic Maya civilization flourished at urban centers such as Tikal and Uaxactún in the Guatemalan Peten lowlands, at Altar de Sacrificios and Seibal on the Pasión River, at Yaxchilán and Piedras Negras on the Usumacinta, at Palenque in the west, at Copan and Quiriguá in the southeast and at hundreds of other sites.
Temple of the Inscriptions at Palenque, Chiapas, the funerary building of King Pacal, who died in 683. Carving monumental inscriptions at Palenque ceased a century later and there was no new elite construction after 800.
Then, something happened to extinguish ancient Maya civilization. The cessation of erecting dated stele poignantly tells the story. From west to east the cities fell. The last dated inscription at Palenque was at 22.214.171.124.7 (A.D. 783), at Piedras Negras at 126.96.36.199.0 (795), and at Yaxchilán at 188.8.131.52.0 (810). At Copan in the southeast, carving monumental inscriptions ceased at 184.108.40.206.5 (822). In the central Maya area, dated inscriptions ended at great Tikal at 10.2.0.0.0 (869), and at Uaxactún at 10.3.0.0.0 (889). The inscriptions record a sort of geographical implosion of Maya culture.
Scholars have investigated for decades what happened to the ancient Maya. In the western areas, fine paste ceramics replaced Classic Maya polychromes, and at Seibal the late sculptures depict non-Maya peoples and elements (790-830).
If this does not suggest invasion, it at least indicates significant cultural change on the western peripheries and up the rivers of the Maya heartland. After considerable population increase in the Late Classic, significant population decline accompanied the collapse. Overuse of resources, such as deforestation, undoubtedly strained sustainability. Drought, such as occurred in the 3rd and 9th centuries, might have played a part. There may have been trade disruption, and over time internecine warfare might have led to social disruption. As in the Anasazi area, such stresses and strains might have led the general population to question the efficacy of ritual and leadership, and undercut popular support for social and political structures. Whatever the causes of the Maya collapse, the effects were catastrophic.
In 1497, Vasco da Gama rounded the Cape of Good Hope and arrived on the coast of eastern Africa in early 1498. There he found a thriving Swahili culture, then 700 years old, from northern Mozambique to southern Somalia. Thus began a colonial power struggle in the western Indian Ocean that disrupted traditional Swahili social, cultural and trading structures. Swahili society did not collapse, but there was major impact all along the coast. Scores of sites, like Kilwa in southern Tanzania and Gedi on the central Kenya coast, were abandoned or greatly reduced in influence. Later, there was Omani presence in eastern Africa, and then the European powers divided the areas into Portuguese, German, British and Italian colonies. Little wonder there were significant transformations of Swahili society.
The Great Mosque at Gedi National Monument, central Kenya coast. Gedi flourished from the early 13th through the 16th centuries and was then abandoned.
There are indications that other factors operated in the abandonment of some Swahili communities. Many of the wells in the northern Swahili world are now salty, suggesting that possible overuse led to contamination of the fresh water by nearby seawater. Neighboring peoples, such as the Orma and Somali, were sometimes hostile to the Swahili and caused relocation. Swahili communities themselves were not always friendly towards each other, and the colonial powers sometimes allied themselves with one community against another. Swahili culture is strong and thriving in many areas today. In the last 500 years the Swahili have weathered many challenges.
Jared Diamond, in his book Collapse: How Societies Choose to Fail or Succeed (2005), studied the fall of cultures from different places and times throughout the world. Based upon his cross-cultural study, Diamond identified five causes, any one or all of which might contribute to cultural collapse: environmental change (such as deforestation, soil and water problems, overuse of resources), climate change, hostile neighbors, disrupted trade, and ineffective societal response to problems. Diamond’s studies make clear that collapse is not confined only to preindustrial societies. Looking forward, Diamond identifies a number of significant problems facing us: destruction of natural habitats (forests, wetlands, coral reefs); overexploitation of fisheries; biodiversity loss, and soil erosion and damage. Energy, water and the photosynthetic ceiling are existing resources that can be depleted, leaving not enough for demand. Toxic chemicals, invasive species and global warming threaten our ability to adapt. Population increase and the impact of many more people exacerbate all the other areas. Bad outcomes include war, genocide, starvation and epidemics.
Diamond makes the point that whatever challenges societies face, collapse is not inevitable. Rather, peoples usually have choices when facing their problems, and how they address their challenges determines their success or failures. We confront very serious challenges right now. Some, like climate change, threaten our very survival. Bringing to bear the perspectives of the humanities will help identify our problems and assist us to implement ways to address them successfully.
Thomas H. Wilson is the Director of the Arizona Museum of Natural History, and Chair of the Arizona Humanities Council.