WHY HUMANS BECAME FOOD PRODUCERS

Lascaux (France)

Although it is tempting to think that a sudden flash of insight about the human ability to control plants and animals might have led ancient peoples to domestication, the evidence points us in different directions. As the following discussion illustrates, there are several false ideas about the motivation to becoming food producers. Contemporary foragers show us that food production did not come about from discoveries, such as that seeds, if planted, grow into plants. These food foragers are perfectly aware of the role of seeds in plant growth, that plants grow better under certain conditions than others, and so forth. Jared Diamond aptly describes contemporary food foragers as “walking encyclopedias of natural history with individual names for as many as a thousand or more plant and animal species, and with detailed knowledge of those species’ biological characteristics, distribution, and potential uses.”  In addition, food foragers frequently apply their knowledge to actively manage the resources on which they depend. For example, indigenous people living in northern Australia deliberately alter the runoff channels of creeks to flood extensive tracts of land, converting them into fields of wild grain. Australian Aborigines choose to continue to forage while also managing the land.
Second, the switch from food foraging to food production does not free people from hard work. In fact, available ethnographic data indicate just the opposite—that farmers, by and large, work far longer hours compared to most food foragers. Finally, food production is not necessarily a more secure means of subsistence than food foraging. Seed crops in particular—of the sort originally domesticated in Southwest Asia, Central America, and the Andean highlands—are highly productive but not stable from an ecological perspective because of low species diversity. Without constant human attention, their productivity suffers.
For these reasons, it is little wonder that food foragers do not necessarily regard farming and animal husbandry as superior to hunting, gathering, or fishing. Thus some peoples in the world have continued as food foragers into the present. However, it has become increasingly difficult for them, because food-producing peoples (including postindustrial societies) have deprived them of more and more of the land base necessary for their way of life. As long as existing practices work well, there is no need for food foragers to abandon them, especially if they provide an eminently satisfactory way of life. Noting that food foragers have more time for play and relaxation than food producers, anthropologist Marshall Sahlins has labeled hunter-gatherers “the original affluent society.” Farming brings with it a whole new system of relationships that disturbs an age-old balance between humans and nature.
In view of what has been said so far, it is puzzling why any human beings abandoned food foraging in favor of food production. Several theories have been proposed to account for this change in human subsistence practices. One older theory, championed by Australian archaeologist V. Gordon Childe, is the desiccation (from the Latin “to dry completely”), or oasis, theory, which is based on environmental determinism. Its proponents advanced the idea that the glacial cover over Europe and Asia caused a shift in rain patterns from Europe to northern Africa and southwestern Asia. When the glaciers retreated northward, so did the rain patterns. As a result, formerly lush regions of northern Africa and southwestern Asia became dryer, and people were forced to congregate at oases for water.
Because of the relative food scarcity in such an environment, necessity drove people to collect the wild grasses and seeds growing around the oases, congregating in a part of Southwest Asia known as the Fertile Crescent. Eventually they began to cultivate various plants to provide enough food for the community. According to this theory, animal domestication began because the oases attracted hungry animals, such as wild goats, sheep, and also cattle, which came to graze on the stubble of the grain fields and to drink. Finding that these animals were often too thin to kill for food, people began to fatten them up.
Although Childe’s oasis theory can be critiqued on a number of grounds and many other theories have been proposed to account for the shift to domestication, it remains historically significant as the first scientifically testable explanation for the origins of food production. Childe’s theory set the stage for the development of archaeology as a science. Later theories developed by archaeologists built on Childe’s ideas and took into account the role of chance environmental circumstances of the specific region along with other specific cultural factors that may have driven change.

The Fertile Crescent

Present evidence indicates that the earliest plant domestication took place gradually in the Fertile Crescent, the long arc-shaped sweep of river valleys and coastal plains extending from the Upper Nile (Sudan) to the Lower Tigris (Iraq). Archaeological data suggest the domestication of rye as early as 13,000 years ago by people living at a site (Abu Hureyra) east of Aleppo, Syria, although wild plants and animals continued to be their major food sources. Over the next several millennia they became full-fledged farmers, cultivating rye and wheat. By 10,300 years ago, others in the region were also growing crops.
This domestication process may have been the consequence of a chance convergence of independent natural events and other cultural developments.The Natufians, whose culture we looked at earlier in this chapter, illustrate this process. These people lived at a time of dramatically changing climates in Southwest Asia. With the end of the last glaciation, temperatures became not only significantly warmer but markedly seasonal as well. Between 6,000 and 12,000 years ago, the region experienced the most extreme seasonality in its history, with dry summers significantly longer and hotter than today. As a consequence of increased evaporation, many shallow lakes dried up, leaving just three in the Jordan River Valley.
At the same time, the region’s plant cover changed dramatically. Those plants best adapted to environmental instability and seasonal dryness were annuals, including wild cereal grains and legumes (such as peas, lentils, and chickpeas). Because they complete their life cycle in a single year, annuals can evolve very quickly under unstable conditions. Moreover, they store their reproductive abilities for the next wet season in abundant seeds, which can remain dormant for prolonged periods.
The Natufians, who lived where these conditions were especially severe, adapted by modifying their subsistence practices in two ways. First, they probably burned the landscape regularly to promote browsing by red deer and grazing by gazelles, the main focus of their hunting activities. Second, they placed greater emphasis on the collection of wild seeds from the annual plants that could be effectively stored to see people through the dry season. The importance of stored foods, coupled with the scarcity of reliable water sources, promoted more sedentary living patterns, reflected in the substantial villages of late Natufian times. The reliance upon seeds in Natufian subsistence was made possible by the fact that they already possessed sickles (originally used to cut reeds and sedges for baskets) for harvesting grain and grinding stones for processing a variety of wild foods.
The use of sickles to harvest grain turned out to have important consequences, again unexpected, for the Natufians. In the course of harvesting, it was inevitable that many easily dispersed seeds would be lost at the harvest site, whereas those from plants that did not readily scatter their seeds would be mostly carried back to where people processed and stored them.
The periodic burning of vegetation carried out to promote the deer and gazelle herds may have also affected the development of new genetic variation. Heat is known to affect mutation rates. Also, fire removes individuals from a population, which changes the genetic structure of a population drastically and quickly. With seeds for nondispersing variants being carried back to settlements, it was inevitable that some lost seeds would germinate and grow there on dump heaps and other disturbed sites (latrines, areas cleared of trees, or burned over terrain).
Many of the plants that became domesticated were “colonizers,” variants that do particularly well in disturbed habitats. Moreover, with people becoming increasingly sedentary, disturbed habitats became more extensive as resources closer to settlements were depleted over time. Thus, variants of plants particularly susceptible to human manipulation had more opportunities to flourish where people were living. Under such circumstances, it was inevitable that eventually people would begin to actively promote their growth, even by deliberately sowing them. Ultimately, people realized that they could play a more active role in the process by trying to breed the strains they preferred. With this, domestication shifted from an unintentional to an intentional process.
The development of animal domestication in Southwest Asia seems to have proceeded along somewhat similar lines in the hilly country of southeastern Turkey, northern Iraq, and the Zagros Mountains of Iran. Large herds of wild sheep and goats, as well as much environmental diversity, characterized these regions. From the flood plains of the valley of the Tigris and Euphrates Rivers, for example, travel to the north or east takes one into high country through three other zones: first steppe, then oak and pistachio woodlands, and finally high plateau country with grass, scrub, or desert vegetation. Valleys that run at right angles to the mountain ranges afford relatively easy access across these zones. Today, a number of peoples in the region still graze their herds of sheep and goats on the low steppe in the winter and move to high pastures on the plateaus in the summer.
Moving back in time prior to the domestication of plants and animals, we find the region inhabited by peoples whose subsistence pattern, like that of the Natufians, was one of food foraging. Different plants were found in different ecological zones, and because of the difference in altitude, plant foods matured at different times in different zones. Many animal species were hunted for meat and hides by these people, most notably the hoofed animals: deer, gazelles, wild goats, and wild sheep.
Their bones are far more common in human refuse piles than those of other animals. This is significant, for most of these animals naturally move back and forth from low winter pastures to high summer pastures. People followed these animals in their seasonal migrations, making use along the way of other wild foods in the zones through which they passed: palm dates in the lowlands; acorns, almonds, and pistachios higher up; apples and pears higher still; wild grains maturing at different times in different zones; woodland animals in the forested zone between summer and winter grazing lands. All in all, it was a rich, varied fare.
The archaeological record indicates that, at first, animals of all ages and sexes were hunted by the people of the Southwest Asian highlands. But, beginning about 11,000 years ago, the percentage of immature sheep eaten increased to about 50 percent of the total. At the same time, the percentage of females among animals eaten decreased. (Feasting on male lambs increases yields by sparing the females for breeding.)
This marks the beginning of human management of sheep. As this management of flocks became more efficient, sheep were increasingly shielded from the effects of natural selection, allowing variants preferred by humans to have increased reproductive success. Variants attractive to humans did not arise out of need but at random, as mutations do. But then humans selectively bred the varieties they favored. In such a way, those features characteristic of domestic sheep—such as greater fat and meat production, excess wool, and so on—began to develop. By 9,000 years ago, the shape and size of the bones of domestic sheep had become distinguishable from those of wild sheep.

Domestication of sheep resulted in evolutionary changes that created more wool. Inset A shows a section, as seen through a microscope, of skin of wild sheep, showing the arrangement of primary (hair) and secondary (wool) follicles. Inset B shows a section of similarly enlarged skin of domestic sheep, showing the changed relationship and the change in size of follicles that accompanied the development of wool.

At about the same time, similar developments were taking place in southeastern Turkey and the lower Jordan River Valley, where pigs were the focus of attention. The recent analysis of pottery vessels from the Near East and southeastern Europe indicates that people were using milk from domesticated cattle in a part of the Fertile Crescent by this time as well.
Some researchers have recently linked animal domestication to the development of fixed territories and settlements. Without a notion of resource ownership, they suggest that hunters would not be likely to postpone the short-term gain of killing prey for the long-term gain of continued access to animals in the future. Eventually, animal species domesticated in one area were introduced into areas outside their natural habitat. To sum up, the domesticators of plants and animals sought only to maximize the food sources available to them. They were not aware of the long-term and revolutionary cultural consequences of their actions. But as the process continued, the productivity of the domestic species increased relative to wild species. Thus these domesticated species became increasingly important to subsistence, resulting in further domestication and further increases in productivity.

Other Centers of Domestication

In addition to Southwest Asia, the domestication of plants and, in some cases, animals took place independently in Southeast Asia, parts of the Americas (Central America, the Andean highlands, the tropical forests of South America, and eastern North America), northern China, and Africa. In China, domestication of rice was under way along the middle Yangtze River by about 11,000 years ago.It was not until 4,000 years later, however, that domestic rice dominated wild rice to become the dietary staple.
In Southeast Asia, decorations on pottery depicting rice dated to between 5,000 and 8,800 years ago document it as the earliest species to be domesticated there. Nevertheless, the region is primarily known for the domestication of root crops, most notably yams and taro. Root crop farming, or vegeculture (The cultivation of domesticated root crops, such as yams and taro), typically involves the growing of many different species together in a single field. Because this approximates the complexity of the natural vegetation, vegeculture tends to be more stable than seed crop cultivation. Propagation or breeding of new plants typically occurs through vegetative means—the planting of cuttings—rather than the planting of seeds.

Early plant and animal domestication took place in such widely scattered areas as Southwest Asia (A1), Central Africa (A2), China (B1), Southeast Asia (B2), Central America (C1), South America (C2), and North America (C3).

In the Americas, the domestication of plants began about as early as it did in these other regions. One species of domestic squash may have been grown as early as 10,000 years ago in the coastal forests of Ecuador; at the same time another species was being grown in an arid region of highland Mexico. Evidently, these developments were independent of each other. The ecological diversity of the highland valleys of Mexico, like the hill country of Southwest Asia, provided an excellent environment for domestication. Movement of people through a variety of ecological zones as they changed altitude brought plant and animal species into new habitats, providing opportunities for “colonizing” to domesticated species and humans alike.
Domestication in the Andean highlands of Peru, another highly diverse region, emphasized root crops, the best known being potatoes (of which about 3,000 varieties were grown, versus the mere 250 grown today in North America). South Americans also domesticated guinea pigs, llamas, alpacas, and ducks, whereas people in the Mexican highlands never did much with domestic livestock. They limited themselves to dogs, turkeys, and bees American Indians living north of Mexico developed some of their own indigenous domesticates. These included local varieties of squash and sunflower.
Ultimately, American Indians domesticated over 300 food crops, including two of the four most important ones in the world today: potatoes and maize (the other two are wheat and rice). In fact, America’s indigenous peoples first cultivated over 60 percent of the crops grown in the world today. They remain not only the developers of the world’s largest array of nutritious foods but also the primary contributors to the world’s varied cuisines.After all, where would Italian cuisine be without tomatoes? Thai cooking without peanuts? Northern European cooking without potatoes? Small wonder American Indians have been called the world’s greatest farmers.
As plant species became domesticated, horticultural societies came into being. These are small communities of gardeners working with simple hand tools and using neither irrigation nor the plow. Horticulturists typically cultivate a variety of crops in small gardens they have cleared by hand. The sophistication of the ancient farming methods as used by Indians in the Amazon rainforest is evident in the research conducted by an international team of archaeologists and other scientists. These ancient methods, which left behind rich dark soils, have important applications for humans today, as explained in this chapter’s Anthropology Applied feature. By reviving these ancient soil-enrichment techniques, we can better manage the rainforests as well as mitigate the damage of climate change.
Considering the separate innovations of plant domestication, it is interesting to note that in all cases people developed the same categories of foods. Everywhere, starchy grains (or root crops) are accompanied by one or more legumes: wheat and barley with peas, chickpeas, and lentils in Southwest Asia; maize with various kinds of beans in Mexico, for example. Together the amino acids (building blocks of proteins) in these starch and legume combinations provide humans with sufficient protein. The starchy grains are the core of the diet and are eaten at every meal in the form of bread, some sort of food wrapper (like a tortilla), or a gruel or thickening agent in a stew along with one or more legumes. Being rather bland, these sources of carbohydrates and proteins are invariably combined with flavor-giving substances that help the food go down.
In Mexico, for example, the flavor enhancer par excellence is the chili pepper; in other cuisines it may be a bit of meat, a dairy product, or mushrooms. Anthropologist Sidney Mintz refers to this as the “core-fringe-legume pattern” (CFLP), noting that only recently has it been upset by the worldwide spread of processed sugars and high-fat foods.

Food Production and Population Size

Since the Neolithic, the global population of humans has grown steadily. The exact relationship between population growth and food production resembles the old chickenand- egg question. Some assert that population growth creates pressure that results in innovations such as food production while others suggest that population growth is a consequence of food production. As already noted, domestication inevitably leads to higher yields, and higher yields make it possible to feed more people, albeit at the cost of more work.
While increased dependence on farming is associated with increased fertility across human populations, the reasons behind this illustrate the complex interplay between human biology and culture in all human activity. Some researchers have suggested that the availability of soft foods for infants brought about by farming promoted population growth. In humans, frequent breastfeeding has a dampening effect on the mother’s ovulation, inhibiting pregnancy in a nursing mother who breastfeeds exclusively. Because breastfeeding frequency declines when soft foods are introduced, fertility tends to increase.
However, it would be overly simplistic to limit the explanation for changes in fertility to the introduction of soft foods. Many other pathways can also lead to fertility changes. For example, among farmers, numerous children are frequently seen as assets to help out with the many household chores. Further, it is now known that sedentary lifestyles and diets emphasizing a narrow range of resources characteristic of the Neolithic led to growing rates of infectious disease and higher mortality. High infant mortality may well have led to a cultural value placed on increased fertility. In other words, the relationship between farming and fertility is far from simple, as explored in this chapter’s Biocultural Connection.

The Spread of Food Production

Paradoxically, although domestication increases productivity, it also increases instability. This is so because those varieties with the highest yields become the focus of human attention, while other varieties are less valued and ultimately ignored. As a result, farmers become dependent on a rather narrow range of resources, compared to the wide range utilized by food foragers. Today, this range is even narrower. Modern agriculturists rely on a mere dozen species for about 80 percent of the world’s annual tonnage of all crops.
This dependence upon fewer varieties means that when a crop fails, for whatever reason, farmers have less to fall back on than do food foragers. Furthermore, the likelihood of failure is increased by the common practice of planting crops together in one locality, so that a disease contracted by one plant can easily spread to others. Moreover, by relying on seeds from the most productive plants of a species to establish next year’s crop, farmers favor genetic uniformity over diversity. The result is that if some virus, bacterium, or fungus is able to destroy one plant, it will likely destroy them all. This is what happened in the Irish potato famine of 1845 to 1850, which caused the deaths of about a million people due to hunger and disease and forced another 2 million to abandon their homes and emigrate. The population of Ireland dropped from 8 million before the famine to 5 million afterward.
This concentration of domesticates and the consequent vulnerability to disease intensify with contemporary agribusiness and factory farming. This chapter’s Globalscape examines the role of pig farming in the current swine flu pandemic that began to sweep the world early in 2009.
The Irish potato famine illustrates how the combination of increased productivity and vulnerability may contribute to the geographic spread of farming. Time and time again in the past, population growth, followed by crop failure, has triggered movements of people from one place to another, where they have reestablished their familiar subsistence practices. Once farming came into existence, its spread to neighboring regions through such migrations was more or less guaranteed. From Southwest Asia, for instance, farming spread northwestward eventually to all of Europe, westward to North Africa, and eastward to India. Domesticated variants also spread from China and Southeast Asia westward. Those who brought crops to new locations brought other things as well, including languages, beliefs, and new alleles for human gene pools.
A similar spread occurred from West Africa to the southeast, creating the modern far-reaching distribution of speakers of Bantu languages. Crops including sorghum (so valuable today it is grown in hot, dry areas on all continents), pearl millet, watermelon, black-eyed peas, African yams, oil palms, and kola nuts (source of modern cola drinks) were first domesticated in West Africa but began spreading eastward by 5,000 years ago. Between 2,000 and 3,000 years ago, Bantu speakers with their crops reached the continent’s east coast and a few centuries later reached deep into what is now the country of South Africa. Being well adapted to summer rains, African crops spread no further, for the Cape of South Africa has a Mediterranean climate with winter rains.

The Culture of Neolithic Settlements

A number of Neolithic settlements have been excavated, particularly in Southwest Asia. The structures, artifacts, and food debris found at these sites have revealed much about the daily activities of their former inhabitants as they pursued the business of making a living. Perhaps the best known of these sites is Jericho, an early farming community in the Jordan River Valley.

Jericho: An Early Farming Community

Excavations at the Neolithic settlement that later grew to become the biblical city of Jericho revealed the remains of a sizable farming community inhabited as early as 10,350 years ago. Here, in the Jordan River Valley, crops could be grown almost continuously, due to the presence of a bounteous spring and the rich soils of an Ice Age lake that had dried up some 3,000 years earlier. In addition, flood-borne deposits originating in the Judean highlands to the west regularly renewed the fertility of the soil.
To protect against these floods and associated mudflows, as well as invaders, the people of Jericho built massive walls of stone surrounding their settlement. Within these walls, which were 2 meters (6½ feet) wide and almost 4 meters (12 feet) high, and behind a large rockcut ditch, which was 8 meters (27 feet) wide and 2¾ meters (9 feet) deep, an estimated 400 to 900 people lived in houses of mud brick with plastered floors arranged around courtyards. In addition to these houses, a stone tower that would have taken a hundred people over a hundred days to build was located inside one corner of the wall, near the spring. A staircase inside it probably led to a mud-brick building on top.
This massive wall—near mud-brick storage facilities as well as peculiar structures of possible ceremonial significance—provides evidence of social changes in these early farming communities. A village cemetery also reflects the sedentary life of these early people; nomadic groups, with few exceptions, rarely buried their dead in a single central location. Close contact between the farmers of Jericho and other villages is indicated by common features in art, ritual, use of prestige goods, and burial practices. Other evidence of trade consists of obsidian and turquoise from Sinai as well as marine shells from the coast, all discovered inside the walls of Jericho.

Extracted from the book 'Evolution & Prehistory- The Human Challenge'  - Wadsworth, Cengage Learning USA, 2011.,Chapter 10, p.233-246. By WILLIAM A. HAVILAND (University of Vermont), DANA WALRATH (University of Vermont), HARALD E. L. PRINS (Kansas State University) and BUNNY MCBRIDE (Kansas State University . Adapted to be posted by Leopoldo Costa.