8.1.2 The Neolithic Revolution in the Americas

As noted earlier, Beringia was submerged under the Bering Strait about eleven thousand years ago, effectively cutting off the Western Hemisphere from the rest of the world. For this reason, technological and cultural developments in Asia, Africa, and Europe were not disseminated to the Americas for many thousands of years. Nor did similar developments in the Americas reach the Eastern Hemisphere. This meant the shift to agriculture in North and South America occurred entirely independently, in three distinct regions that developed agricultural traditions of their own. These were the Andean region, Mesoamerica, and the upper reaches of the Mississippi River valley in the Eastern Woodlands.

The earliest evidence for the shift to agriculture, or the Neolithic Revolution, in the Americas has been found in the Andean region (Table 8.1). There, the domestication of plants and animals developed piecemeal and gradually, and its precise origins are not entirely clear. In some parts of the region, the domestication of camelids such as llamas, guanacos, and alpacas for meat and later wool may have begun as early as 7400 BCE. Similarly, the domestication of the guinea pig for food may have begun as early as 6200 BCE, or as recently as 4400 BCE depending on the evidence used. As for edible plants, some discoveries place the earliest cultivation of squash and bottle gourds at around 8000 BCE. The dates scientists have discovered for domesticated plants like the potato are also remarkably early. Genetic testing of the potato indicates that this rugged tuber may have been domesticated from a wild variant between 8000 and 6000 BCE. Another Andean cultivated plant, quinoa, may have been grown as animal feed about 5000 BCE and later eaten by humans.

Regardless of when or how the process began, by 3000 BCE, at least partially settled agricultural communities were becoming more common in the Andes region. The similarities among sites in central coastal Peru have led archaeologists to describe them as belonging to one larger culture, sometimes called the Norte Chico or the Caral civilization. A few sites were quite large, such as Aspero, El Paraiso, and Caral (Figure 8.8). Each included multiple mounds and was topped by architectural complexes arranged in a U-shaped pattern. Of the three, Caral is the largest, with a great number of mounds spread across a large area. The largest mound, or the main temple, measures ninety-two feet high and is almost five hundred feet long at its base. Building such a mound would have required a dedicated workforce, suggesting a highly organized society.

Archaeological evidence indicates that the people who lived at Caral relied primarily on fish and both wild and domesticated crops, such as squash, beans, avocados, and potatoes. As for the social organization of the Norte Chico, we can only speculate, but based on an examination of the burial sites and the likely ritual significance of many of the ruins, there appear to have been social divisions and organized spiritual or religious practice (Figure 8.9). Given the large-scale architecture and the need for laborers, it is also almost certain there was some type of powerful hereditary leadership. And, apart from the structural similarities across the different sites, evidence suggests there were connections between them. For example, the smaller sites along the coast appear to have supplied the larger inland Caral site with necessary marine resources. There may then also have been some type of ruling system over all the various sites, rather than just a similar culture that united them. However, there is no solid evidence to date to support that conclusion.

Given the great distance and climate differences between the Andean region and Mesoamerica, the agricultural traditions developed in South America were not easily disseminated north into Mesoamerica in Neolithic times. However, it does appear that at least one important Mesoamerican domesticated crop did reach the Andes. This crop was maize, colloquially called corn in the United States. Maize was domesticated from a type of wild edible grass known as teosinte between 5000 and 3000 BCE. While debate continues about how exactly that process occurred, it is generally accepted that human intervention transformed the thick wild grass into the large, sturdy, cob-producing plants we know today. Once domesticated, maize became an important staple carbohydrate in Mesoamerica and led to the rise of large populations. The earliest domesticated maize emerged in either the Tehuacán Valley or the highlands of Oaxaca, from which it was disseminated around Mesoamerica and eventually far beyond. Evidence for Mesoamerican maize in the Andean region dates to about 1600 BCE. There it was commonly used to make a fermented alcoholic drink and popcorn, but it never became an important part of the diet in the way it did in Mesoamerica.

By around 2500 BCE, a shift toward cooler and wetter conditions in Mesoamerica, combined with the availability of domesticated maize, gave birth to a number of agricultural villages in the region. The residents of these villages typically continued hunting and gathering, but they soon recognized the great advantage of growing maize. Over time, the labor demands of doing so and the caloric value of maize led to a steady decline of gathering activities, resulting in exclusively sedentary agricultural communities. Populations grew, necessitating more farmland to raise even more maize. In this way, maize cultivation expanded across the core regions of Mesoamerica, including southern Mexico and parts of Guatemala. By 2000 BCE, sedentary agricultural settlements had become common across these areas. As occurred in regions around the world during the shift from hunting and gathering to sedentary agriculture, new social hierarchies developed as work became more specialized. These hierarchies were related to not only wealth accumulation but also the rise of leadership power.

At some point in the late third millennium BCE, maize was eventually disseminated to what is now the southwestern United States. There, groups began using a form of the plant that had been adapted to the drier environment. At this time, it was merely a supplement to other gathered plants, so peoples in this area remained mostly migratory for some time. Over many centuries, they experimented with varieties of maize. They found ways to grow it in high-elevation areas, and they discovered which areas produced the best results, such as floodplains where irrigation occurred naturally.

In the Eastern Woodlands, people had been experimenting for thousands of years with naturally occurring edible plants like goosefoot, sunflower, bottle gourds, and squash (Figure 8.10). The use of bottle gourds as containers was an ancient practice in the Eastern Woodlands, and the cultivation of bottle gourds may have been encouraged as long ago as 5000 BCE. Similarly, the domestication of sunflowers, useful for their oily and nutritious seeds, appears to have begun by about 2300 BCE. However, by about 2000 BCE, groups in this region began making concerted efforts to increase their food supply by altering the physical environment, clearing small plots of land to more carefully cultivate these wild plants. Through migration, some transported seeds for certain plants to other areas. Successful techniques for encouraging the growth of these plants were passed from generation to generation. In this way, agricultural cultivation emerged in the Eastern Woodlands independently.

By the time Eastern Woodlands peoples began cultivating their own native plants around 2000 BCE, they had also begun living in more clearly defined territories. Yet there was communication and trade between different areas. Certain types of stone, copper materials, and shells from the coastlines could pass from one small group to another and in the process move many hundreds of miles. Groups from around a localized region may also have participated in certain ceremonies together. Over time, the increasing availability of food and exposure to wealth in the form of traded materials led to social transformations like a reduction in the egalitarianism common among hunter-gatherers. Burial sites and the increasing number of earthen mounds built from the period demonstrate this.

Groups in the Eastern Woodlands remained small, likely no more than one hundred or so members in most places. There were a few exceptions, such as at the large Poverty Point site in northern Louisiana (Figure 8.11). There, beginning around 1000 BCE, several U-shaped concentric mounds were constructed to form an impressive and unusual ceremonial site. The exact purpose of the site and the social organization of the people who built it are not known, but it likely had some ritual significance, and those who lived in and around it employed both hunter-gatherer and agricultural strategies. It was an active site for about three hundred years before being abandoned for reasons unknown.