Horticulture and pastoralism brought significant changes to human ways of life, but the domestication of certain large animals had an even bigger impact. Cattle and water buffalo were domesticated in some parts of Asia and North Africa in which they occurred naturally by at least 7000 B.C.E., and horses, donkeys, and camels by about 4000 B.C.E. All these animals can be trained to carry people or burdens on their backs and to pull loads dragged behind them, two qualities that are rare among the world’s animal species. In many parts of the world, including North America and much of South America and sub-Saharan Africa, no naturally occurring large species could be domesticated. In the mountainous regions of South America, llamas and alpacas were domesticated to carry packs, but the steep terrain made it difficult to use them to pull loads. The domestication of large animals dramatically increased the power available to humans to carry out their tasks, which had both an immediate effect in the societies in which this happened and a long-term effect when these societies later encountered societies in which human labor remained the only source of power.

The pulling power of animals came to matter most, because it could be applied to food production. Sometime in the seventh millennium B.C.E., people attached wooden sticks to frames that animals dragged through the soil, thus breaking it up and allowing seeds to sprout more easily. These simple scratch plows were pulled first by cattle and water buffalo, and later by horses. Over millennia, moldboards — angled pieces that turned the soil over, bringing fresh soil to the top — were added, which reduced the time needed to plow and allowed each person to work more land.

Using plows, Neolithic people produced a significant amount of surplus food, which meant that some people in the community could spend their days performing other tasks, increasing the division of labor. Surplus food had to be stored, and some began to specialize in making products for storage, such as pots, baskets, bags, bins, and other kinds of containers. Others specialized in making tools, houses, and other items needed in village life, or for producing specific types of food, including alcoholic beverages made from fermented fruits and grains. Families and households became increasingly interdependent, trading food for other commodities or services. In the same way that foragers had continually improved their tools and methods, people improved the processes through which they made things. Sometime in the fifth millennium B.C.E., pot makers in Mesopotamia invented the potter’s wheel, which by a millennium later had been adapted for use on carts and plows pulled by animals. Wheeled vehicles led to road building, and wheels and roads together made it possible for people and goods to travel long distances more easily, whether for settlement, trade, or conquest.

Stored food was also valuable and could become a source of conflict, as could other issues in villages where people lived close together. Villagers needed more complex rules than did foragers about how food was to be distributed and how different types of work were to be valued. Certain individuals began to specialize in the determination and enforcement of these rules, and informal structures of power gradually became more formalized as elites developed. These elites then distributed resources to their own advantage, often using force to attain and maintain their power.