In the past 15,000 years, epochal social and cultural changes have created fundamentally different relationships between humankind and the environment. One of the most important innovations has been the domestication of plants and animals, a major factor in the gradual establishment of agriculture as the world’s predominant economic base. The development of agriculture brought an increase in sedentism, in which human groups lived in more or less permanent communities.

Associated with farming was the domestication of animals and, in some societies, nomadic pastoralism. By about 6000 B.C., animal husbandry provided a relatively widespread and stable source of high-quality protein in the Near East. Moreover, the protein was typically produced in ways that did not compete directly for agricultural land resources. Domestic herds grazed on agricultural land after the harvest (Bentley 1987) or on land that was fallow, marginal, or inadequate for farming.

The greater control that agriculture and the domestication of animals gave people over food production resulted in food surpluses. Surplus food created the potential for the emergence of specialists such as craftsmen, merchants, and a ruler class, which are essential components of urban society, another major social change. Urbanism began in the Near East during the Chalcolithic Age (c. 4000–3200 B.C.) but had its major efflorescence during the Early Bronze Age (c. 3200–2000 B.C.)

The advent of agriculture, the domestication of animals, and the development of urbanism had a significant impact on human health. Although agriculture dramatically increased the calories that could be produced by a given individual, the emphasis on a few cultigens increased the vulnerability of agricultural societies to famine and malnutrition (Cohen 1984a).