Emergence and Collapse of Early Villages in the Central Mesa Verde

AN INTRODUCTION

Timothy A. Kohler and Mark D. Varien

Two hundred and forty years after the last Pueblo people left Colorado, Hernán Cortés de Monroy y Pizarro—or maybe it was Quetzalcoatl—stepped onto the shores of Veracruz. Arriving at the Aztec capital of Tenochtitlan less than seven months later, the Spanish had no trouble recognizing kings and slaves, temples and markets, gods and warriors, and all manners of artifacts and other institutions, none of which had existed when the ancestors of these two societies last lived together in Eurasia. What accounts for the surprising mutual intelligibility of social forms between two societies that had shared their last common biological and cultural ancestors tens of thousands of years ago?

Undoubtedly the shared biology (proximate by the standards of biological evolution) and perhaps the shared culture (which, however, was very distant by the more rapidly changing standard of culture itself) had some effect on channeling development in certain directions rather than others. But another possibility that needs to be considered is that winnowing of less-efficient forms by selection through competition among groups may have shaped these otherwise independent historical trajectories. Some solutions to the puzzle of how to induce people to cooperate with large numbers of other unrelated people probably work better than others, and, if invented independently, might be maintained. This logic helps us understand, for example, why markets appeared alongside older reciprocal exchange systems as Pueblo peoples began to concentrate in the northern Rio Grande region of New Mexico in the A.D. 1300s (Kohler, Van Pelt, and Yap 2000). Over long enough periods, solutions that are markedly less workable may tend to be supplanted, whether through lethal intergroup competition, nonlethal cultural group selection, selective migration, or related processes (see review in Salomonsson 2010).

But such arguments are plausible only if we can show that adaptation, a concept we are borrowing from biology, has some relevance for understanding cultural behavior. This might seem a modest claim: we are not, for example, proposing that natural selection is a "universal acid" explaining all aspects of culture and its contents, as Daniel Dennett (1995) sometimes seems to do. But as we shall see, even this modest claim would be dismissed by some.

Societies are likewise in constant interaction with the environments they inhabit. They modify those environments by accident and on purpose, affecting their short-and long-term productivity. How could it not be the case that this also affects the success of the societies? One common characteristic of Neolithic societies is the rapid population growth they experience. If per capita use of resources remains constant as population grows, resources that regenerate slowly will be drawn down. This may soon require societies to move to previously uninhabited areas, if they are available—but eventually, this option will be impossible and new patterns of resource usage must be developed. Societies unable to innovate these patterns will be displaced by those that can.

The general growth of Neolithic populations also favors those groups that can effectively coordinate the largest numbers of people, since large cohesive groups can displace smaller or less cohesive groups, or resist displacement by others. These two pressures—building larger sedentary groups and not depleting the environment—are at odds with each other. This contributes to the dynamic character of the Neolithic record in most areas; in finding an effective compromise between these two opposing forces, societies are driven to a position on a metaphorical fitness landscape where they become extremely vulnerable to external perturbations such as climate change.

Eventually we would like to examine how these processes play out in Neolithic societies all over the world. (We suspect that they are completely general.) Unfortunately, there are few places where the Neolithic sequences are known well enough to make this possible in any convincing detail. In this book we analyze these social and "socionatural" processes through an extended case study set in southwestern Colorado between A.D. 600 and A.D. 1300. This is a fascinating 700 years that takes us, in its first two centuries, from the arrival of small groups of maize farmers in an almost uninhabited mesa and canyon country to the emergence of some of the Southwest's earliest and largest villages. But around 100 years later, by A.D. 900, most of the villages in our study area had disbanded and their inhabitants departed for the south or west. The remaining house holds once again lived mostly in small hamlets until about A.D. 1080, when a new wave of colonists arrived from the south, bringing a differently organized village lifeway backed by a novel, powerful political and religious system that united most of the eastern Southwest. Within 200 years this wave, too, receded, again to the south, leaving behind the famous ruins of Mesa Verde National Park and the less-well-known but more populous district that includes Canyons of the...