New World Farmers
While Old World Neolithic cultures generally relied on agricultural practices that linked domesticated cereal grasses together with herd animals, the farmers of the Americas focused almost exclusively on plant resources. Most of these plants had very limited ranges, but one important cereal grass— maize, or corn—came to dominate prehistoric Native American agriculture nearly everywhere it could be grown . Cereal grasses suitable for domestication were abundant on several continents, but the people of the Old World brought more of those species under control. Except for maize, whose wild ancestor may at first have been used in a different way, human cultural behavior in the New World did not induce the same genetic transformations in American grasses as it had in the Old World.
New World Domesticates
Considered together, the products of New World farmers make up a remarkable catalog of familiar plants, many of which were domesticated between 10,000 and 7,000 ya (Iriarte, 2009). Besides maize, the list includes important staple foods like white potatoes, sweet potatoes, yams, manioc, many bean varieties, peanuts, sunflowers, and quinoa (Chenopodium sp.). Nearly as important, but not staples, are such domesticated vegetables and fruits as sweet peppers, chili peppers, tomatoes, squashes, and pumpkins, along with pineapples, papayas, avocados, guavas, and passion fruit. Vanilla and chocolate came from American tree beans. Tobacco, coca, and peyote were major stimulants, and a host of other American plant domesticates had medicinal, utilitarian, or ornamental uses long before the arrival of the Europeans. The principal New World domesticates were developed in several locations in Mexico and in South America, but the use of a few of these plants eventually spread far beyond the regions in which they were first domesticated. One domesticated plant, the bottle gourd (Lagenaria siceraria), appears to have had a much different origin than other New World domesticates. It was long suspected that the bottle gourd reached the New World by floating across the Atlantic Ocean from Africa, where it occurs in the wild, but genetic research shows that the closest relatives of the oldest New World specimens were from northeastern Asia. Based on AMS radiocarbon dates of gourd samples and analyses of DNA markers, the domesticated bottle gourd was present in the Americas by 10,000 ya and may have been carried from Asia by Paleo- Indian colonists (Erickson et al., 2005)! Aside from the dog, which also accompanied the first humans into the New World, domesticated animals had a relatively minor role in the Americas, as we noted earlier (see pp. 353–354). The llama and alpaca, both of which are long-haired relatives of the camel and are found in highland South America, were the only large domesticated species (Stahl, 2008). Other domesticates—the guinea pig (raised for its meat, not as a pet) and Muscovy duck in western South America, turkeys in Mexico—were small in size and not very important beyond their localized distribution areas.
Mexico
Recent archaeological and genetic research is forging a new understanding of the development of Mexican agriculture and of the beginnings of agriculture and settled farming communities in the Americas. Of the more than 100 plant species fully domesticated by Native Americans in Mexico, maize (a grass), beans (legumes), and squashes (cucurbits) ultimately attained the widest prehistoric significance for food purposes (Iriarte, 2009). Today’s many varieties of maize make it one of the world’s primary staples . Maize probably originated somewhere in the valleys of southern and western Mexico and was one of several plants domesticated during the early Holocene. At the Xihuatoxtla site in the Balsas Valley of southwestern Mexico , maize starch grains and phytoliths have been recovered from the surfaces of grinding stones and other artifacts dating to about 8,700 ya (Piperno et al., 2009; Ranere et al., 2009). Similar evidence of early agriculture is reported from the Gulf Coast lowlands of Mexico, as well as at sites in Central America and northern South America (Iriarte, 2009). But early Mexican agriculture was not just all about maize. Other plants were being brought under cultivation in southern Mexico around the same time, including several kinds of beans, squashes, gourds, chili peppers, avocados, and cactus fruit (Flannery, 1986; Smith, 1997). While long believed to have been little more than a dietary supplement for hunter-gatherers for a long time, some of these crops were actually capable of supporting communities. Others played important social and ritual roles in Mesoamerica. The best example of the latter is a tree crop, cacao (the basic ingredient of chocolate). It never became a major prehistoric food crop, but it was ritually important both as a beverage and in solid form. Cacao use began in the Maya lowlands between 3,900 and 3,700 ya (Powis et al., 2007). Maize, squash, and the common bean make up an important trinity of prehistoric Native North American crops. The common bean appears to have been domesticated in west-central Mexico (and again independently in Peru). Comparative analysis of the genetic diversity of wild and domesticated common beans points to the Lerma and Santiago basin of western Mexico as the region in which the common bean was first domesticated in Mexico (Kwak et al., 2009). Like the common bean, squashes were probably independently domesticated in several parts of the Americas. In Mexico, domesticated seeds of pumpkin-like squashes from Guila Naquitz Cave, in Oaxaca, are nearly 10,000 years old. Rinds of domesticated squash have also been recovered from 8,700-year-old contexts at Xihuatoxtla, in northern Guerrero (Ranere et al., 2009). The maize-beans-squash crop trinity eventually came together in the milpa intercropping system that was an important part of Mexican agriculture.
South America
Given the analytical value of genetic data and plant microfossils, research into the history of domestication and agriculture in South America is making rapid strides. The current focus is on several major questions. First, what were the relative roles of marine resources and agricultural products throughout prehistory on the continent’s west coast? Second, to what extent did Mexican crops, particularly maize, contribute to South American agriculture? Finally, what was the nature of Amazonian agriculture in eastern South America? Sites in southwestern Ecuador have yielded squash and gourd (cucurbit) phytoliths that date to 12,000–10,000 ya. Their large size suggests they’re from domesticated plants; if this is true, it means that the beginnings of food production in lowland South America began about the same time as in Mesoamerica, and maybe even earlier (Piperno and Stothert, 2003). Sediment cores and other geomorphological evidence indicate that the periodic climatic phenomenon known as El Niño became established between 7,000 and 5,000 ya in the Pacific (Sandweiss et al., 1996). El Nino events are triggered when a persistent trough of atmospheric low pressure forces warm equatorial waters southward along South America’s west coast, partially displacing the northward flow of deep cold currents. El Nino typically disrupts the maritime food chain and dramatically disturbs precipitation patterns over land, bringing excess rainfall and flooding to some areas, drought to others. El Nino returns every four years or so, on average, and some episodes are more severe or last longer than others. Early farming in coastal Peru seems somewhat related to the El Nino pattern (Piperno and Pearsall, 1998). At Paloma (see Fig. 14-18), a short distance south of present-day Lima, summer fishing expeditions had extended into yearround reliance on large and small fish species, shellfish, sea mammals, turtles, and seabirds. Midden contents, analyses of coprolites, and high strontium levels in human skeletons confirm the nearly exclusive role of sea resources at some sites by 5,000 ya (Moseley, 1992). The fishers also began experimenting with nonlocal plant crops, using bottle gourds for carrying water and adding several kinds of squashes and beans to their diet. By about 4,500 ya, they had taken up small-scale horticulture in nearby river valleys, growing cotton for nets and cloth and, significantly, supplementing their predominantly seafood diet with at least 10 more edible plants. While they maintained their basic maritime focus for centuries to come, coastal Peruvians may have decided that a greater variety of foods helped to minimize the periodic shortfalls in sea resources that they could expect with most El Nino events every few years. The intercontinental dispersal or exchange of American cultigens is a topic of active archaeobotanical research and debate (Smith, 1999; Iriarte, 2009). Maize may have reached coastal South America not long after being domesticated in southern Mexico . Genetic data, preserved plant macro and microfossils, maize motifs on pottery, and even the impression of a kernel in the wall of a fired clay vessel, as well as increases in both grinding stones and human dental caries, attest to the early presence of maize in this region. Maize eventually became a significant food source for all the native cultures of western South America. Sixteenthcentury Spanish chroniclers noted that many different varieties of maize accommodated Peru’s demanding climatic and topographical diversity from sea level to 6,500 feet, with potatoes taking over at higher elevations. Each of these varieties, developed through careful selection and hybridization, probably derived from a common ancestral form of Mexican maize. Plant cultivation was under way in a few highland areas of South America before 8,500 ya. Nonfood species useful for fiber, containers, tool shafts, bedding, and medicines were tended even more often than edible plants around Guitarrero Cave , in the Andes Mountains (Lynch, 1980). Native tree fruits, broad lima beans, smallseeded quinoa, and several starchy tubers were among the local food crops grown there (Lynch, 1980). One of these ancient root crops was the white potato, and when eventually adopted into Old World agriculture and cuisine, it became today’s familiar baked potato, Dutch frites met, and Indian alu masala. Other native South American cultigens were developed in the tropical forests on the eastern slopes of the Andes or in the humid Amazon basin to the east. Roots of manioc shrubs and sweet potatoes became dietary staples in the eastern lowlands, supplying abundant carbohydrate energy but little else. Peanuts added some protein and fats to the starchy diet, but fish and insects remained essential food resources for most of the natives of Amazonia, since their small gardens alone generally couldn’t sustain them entirely.
Southwestern United States
Agriculture based on maize and other crops spread into the American Southwest from Mesoamerica. The big questions are currently why, when, and how this northern dispersal of agriculture took place. Researchers are currently examining two possible explanations (Merrill et al., 2009). One view is that maize agriculture was brought to the Southwest by farmers who migrated northward in search of suitable planting areas. Peter Bellwood (1997, 2005, pp. 240–244) and Jane Hill (2001, 2010) argue that these farmers were Proto- Uto-Aztecan speakers, who began to spread from their Mesoamerican homeland across the region around 3,500 ya. This hypothesis, if supported by data, would explain the diffusion of agriculture into the American Southwest, as well as the subsequent distribution of the Uto-Aztecan language family. A competing hypothesis questions the timing and role of the spread of the Proto-Uto-Aztecan language family and argues that maize agriculture entered the Southwest from Mesoamerica as the result of “group-to-group diffusion,” not migration (Merrill et al., 2009, 2010). The proponents of this view argue that Proto-Uto-Aztecan speakers were more likely to have been Great Basin foragers, not Mesoamerican farmers, and that the breakup of the Proto-Uto-Aztecan speech community actually began in the Great Basin nearly 9,000 ya. Merrill and colleagues (2009) further note that mtDNA research does not support a Mesoamerican homeland for the Proto- Uto-Aztecan language family (also see Kemp et al., 2005). The weight of evidence currently supports the “group-to-group” diffusion hypothesis. The earliest maize is present in the American Southwest around 4,100 ya (Merrill et al., 2009). Notably, other important Mesoamerican cultigens, such as squash, amaranth, beans, and cotton, did not arrive in the region at the same time as part of a coherent agricultural complex, but reached the Southwest separately over the course of the next two millennia. Between 2,300 and 1,300 ya, reliance on these domesticated products promoted increased population density and overall cultural elaboration, resulting in the emergence of several distinctive prehistoric cultural traditions in the Southwest . Archaeologists distinguish each of these regional traditions based on such features as pottery style, architecture, religious ideas, and sociopolitical organization (Plog, 1997). The Hohokam of southern Arizona were growing both food and cotton by 1,500 ya and possibly much earlier, irrigating their gardens through an extensive system of hand-dug channels that conveyed water from the Gila River or its tributaries. By around 1,000 ya, architecture and artifacts on large Hohokam sites, such as Las Colinas and Snaketown, near Phoenix, reveal links to Mexican centers to the south. They include ball courts and platform mounds as well as copper bells, parrot feathers, and other Mesoamerican products (Haury, 1976). The Hohokam crafted human figurines and shell and turquoise ornaments in sufficient quantities for trade (Crown, 1991). The Casas Grandes district of northern Chihuahua, Mexico, may have served as a major exchange corridor between Mesoamerica and the Southwest (DiPeso, 1974). But whether the Hohokam maintained direct contact with Mexican civilizations or simply participated in the diffusion of ideas and products passed along trade routes is a matter for debate. The Mogollon, whose prehistoric culture straddled southern New Mexico and Arizona, lived in pit houses until about a.d. 1000. Around that time, they began constructing aboveground room blocks and—in imitation of their northern neighbors—creating boldly painted black-on-white pottery. Archaeological traces of the Mogollon faded a century or more before Europeans arrived in the mid-1500s, possibly as its people drifted southward into Mexico. In the Four Corners region to the north, prehistoric farmers known to archaeologists as the Anasazi built impressive prehistoric masonry villages and towns, called pueblos, beginning around a.d. 900. With their large scale, picturesque settings, and excellent preservation, some Anasazi sites— including Chaco Canyon , in New Mexico, and the so-called cliff dwellings of Mesa Verde , in Colorado— are among the most famous archaeological locations in the United States. Anasazi towns consisted of multiroom, multistory residential and storage structures and usually included underground ceremonial chambers, called kivas. Their compact sites were situated with good access to the limited agricultural lands and scarce water supply of this high and arid region. The rise of the Chaco Canyon towns and related villages was probably stimulated by a brief period of increased rainfall and sustained by social factors such as political or religious ideology, trade, and regional strife. A growing body of evidence also points to Chacoera warfare and terrorism among the Anasazi, extending even to cannibalism (White, 1992; Turner and Turner, 1999). Beginning in the mid-1100s, the Anasazi abandoned Chaco and, eventually, most of the region’s other large pueblos. By then, shifting precipitation patterns associated with a general warming period were leaving marginal zones of the Southwest, especially the Colorado Plateau, without adequate rainfall to grow maize (Cordell, 1998). As the drought worsened through the late 1200s, Anasazi townspeople persisted in a few places like Mesa Verde , where they built their communities into easily defended niches in the steep cliffs and tilled their fields on the canyon rim by day. By a.d. 1300, even Mesa Verde stood empty; the Anasazi of the Four Corners had dispersed toward the south and southeast to become the people known today as Hopi, Zuni, and the Rio Grande Puebloans.
Eastern North America
The earliest domesticated plant in eastern North America was the bottle gourd, a specimen of which has been found with a 7,300-year-old burial at Windover, Florida (Doran et al., 1990). Bottle gourds, which were grown for use as containers, not as food, were probably domesticated in the Old World and entered North America with the earliest human inhabitants. During the early Holocene, aboriginal peoples developed an independent center of domestication and cultivation in eastern North America (Price, 2009). The first domesticated plant other than the bottle gourd was squash about 5,025 ya, followed soon by sunflower and marsh elder (sumpweed). These plants are associated with ancient campsites and shell heaps along major river valleys, where, about 4,000 ya, people maintained “incidental gardens” of plants that supplemented traditional foraging activities (Smith, 1999; Smith and Yarnell, 2009). Over the next millennium, several more native species, such as knotweed, may grass, and little barley, were added to the cultivated plants of the region. Stone hoes also began to appear on sites in the Illinois River valley at about the same time (Odell, 1998). It wasn’t easy to harvest and process these weedy, small-seeded species, so they probably weren’t much more than supplements to a diet of wild foods. Still, the river valleys of the Southeast and the Midwest, as well as the rich forests covering much of the Northeast, clearly supported large, successful communities even without maize agriculture. For example, the widespread practice of mound building and associated death and burial rituals began long before any significant reliance on maize. As we’ve seen, Late Archaic hunter-gatherers also constructed major mound groups that, like those at Poverty Point, Louisiana (see Chapter 13), were considerably more than mere stacks of dirt. Maize was not present in eastern North America until around 2,150 ya, and it appears to have had little economic impact at first. It’s not until after 1,200 ya in the Southeast and around 800 ya in the Northeast that we begin to see archaeological evidence of a widespread economic commitment to agriculture, possibly brought about by new varieties of maize and the introduction of domesticated beans (Smith, 1992; Hart and Scarry, 1999). Even then, wild nuts, seeds, fish, and game were staples in the diets of many groups. In the broad river valleys of the Southeast, maize farming was the economic mainstay of Mississippian chiefdoms . Mississippian elites relied on elaborate rituals and displays of valued symbols to enhance their privileged positions. Populations and ceremonial centers throughout the region were linked by exchanges of symbolic copper, shell, pottery, and stone items, as well as a common focus on the construction of towns centered on impressive earthen mound groups that flanked public spaces or plazas (Lewis and Stout, 1998; Emerson and Lewis, 2000). Most buildings that flanked the plazas were erected on substructure or platform mounds. Some of these buildings were dwellings; others were charnel houses and other community structures. The houses and workplaces of the town’s rank and file clustered around these mound-and plaza complexes (Fig. 14-23). The Mississippian site of Cahokia, located below the junction of the Missouri and Mississippi rivers near St. Louis, once boasted some 120 mounds (Milner, 1998; Pauketat and Wright, 2004). The primary earthwork was Monks Mound (Fig. 14-24), as long as three football fields and as high as a six story building—the largest prehistoric structure north of Mexico. Cahokia’s homes and garden plots spread over 6 square miles beyond the log stockade that enclosed the central mounds and elite living area. Fields of maize, squash, and pumpkins extending along the river floodplain provided the harvest sheltered in many storage pits and granaries (Iseminger, 1996).
Other New World Regions
Elsewhere in the Americas, farming hadn’t gained much importance even by the time Europeans were arriving with their own ways of life and their Old World domesticates (Brown, 1994). In fact, throughout much of western and northern North America and in some South American regions, hunting, fishing, and gathering were still the principal ways of making a living. These lifeways persisted in part because the more productive American domesticates, especially those native to warm temperate zones, couldn’t be introduced and maintained in other geographical settings without sustained effort. Even so, it wasn’t always a question of whether farming was possible; it was often a matter of choice. Maize was far from an ideal crop, even where it could be grown most readily. Old World domesticated cereal grasses, including wheat, barley, oat, rye, millet, and rice, grew in dense stands that farmers could harvest readily with a sickle and clean by threshing and winnowing. Maize, the primary New World cereal grass, required more space per plant and more moisture during its long growing season, and it was much harder to harvest and process by hand. What’s more, these agricultural products could seldom beat the nutritional value of a mixed diet obtained through foraging. Maize itself is deficient in lysine (an amino acid) and niacin and contains a chemical that may promote iron-deficiency anemia. Similarly, in the Amazon basin in South America, the peoples who domesticated manioc, sweet potatoes, and other starchy root crops before 1,500 ya found that these foods supplied bulk and carbohydrates but little protein—a deficiency the people of the Amazon overcame by continuing to rely on hunting, fishing, and gathering.