By around 8000 B.C., global warming resulted in the retreat of the Ice Age glaciers. This retreat allowed early humans to move into new areas. As temperatures rose, the growing season became longer. Wild grasses spread and were domesticated by humans—that is, humans learned to grow and tend the grasses. This skill provided humans and grazing animals with more grain to eat.

The Domestication of Animals

Early humans learned to domesticate animals such as sheep and goats around 9000 B.C. People raised them for food and clothing. Domesticated animals offered a reliable source of meat and milk products. After people killed an animal, they used its skin to make clothing and shelters. They made harpoons, needles, and other tools from the bones.

The Domestication of Plants

Food gatherers noticed that grain sprouted from spilled seed. Around 8000 B.C., people got the idea of agriculture—planting seeds to raise crops. The Agricultural revolution is the name given to the shift from food gathering to food raising. The agricultural revolution brought about changes in tools and technology. People made hoes to loosen the soil, sticks to dig holes, and sickles to harvest grain.

Early farmers practiced slash-and-burn agriculture. They cut and then burned trees and brush to clear land for crops. After a number of growing seasons, soil often became poor. People then moved on to a new location. People learned to be better farmers as their tools improved. Groups often remained in the same areas instead of moving around every few years. They began to develop permanent settlements.

Farming Villages Develop

Fertile soil produced bigger and better crops. This attracted farmers. River valleys had soil that was especially rich. Their soil was better than that in fields that had been cleared by slashing and burning. Farmers settled in villages and went out to the fields to work. Villages grew to hold several thousand people. People lived in shelters made of mud, bricks, logs, and hides. Village life provided many advantages. Food was more plentiful. People living in larger groups could more easily withstand attacks by nomadic bands. Village life also had disadvantages, including the risks of fire, disease, and flood.

About 8000 B.C., people in different parts of the world began to develop farming. Early farmers invented new methods of farming. River Valleys in Africa and Asia Early farming developed in areas where water was available, such as in river valleys. These included the Huang He in China and the Nile in Africa. African farmers along the Nile were among the first to use irrigation—the watering of crops. They built irrigation systems of dikes and canals.

Farming in the Americas developed later than in the rest of the world. It developed mainly in upland regions—plateaus and other flat areas at fairly high elevations. Farmers in the Americas developed techniques suited to the environment. The terracing of land to create flat areas helped adapt the land for raising crops such as corn, beans, potatoes, and squash.

Surpluses Boost Development

As agricultural techniques improved, farmers sometimes produced surpluses—more than what they needed to survive. For example, farmers might grow more grain than their families or village could use. The extra was an economic surplus. Surpluses in early farming villages were not limited to food. Surpluses also included materials for making cloth and other products. Sheep raisers, for example, may have had surplus wool. Surpluses of food and other materials in good seasons helped villages survive bad seasons.

As farmers began producing surpluses, not everyone had to raise food. People began specializing in other kinds of work. A specialization is a skill in one kind of work. Potters and weavers probably were among the first to specialize. They made products that everyone could use. Potters made vessels for carrying and storing water and food. Weavers created cloth from spun cotton, wool, and flax—the plant from which linen is made. Potters and weavers traded their products for food. Certain people in a community were regarded as holy. These holy people, or shamans, interpreted natural events such as rain or fire. They explained the meaning of a good or bad harvest. They were also healers. They were thought to be in contact with the spiritual world. Such people evolved into the priests of the first cities.

The way of life in a village was new and very different. Hunter-gatherers led a nomadic life, moving from place to place. Villagers settled in one place and no longer depended on hunting and gathering for food. Instead, farmers worked to raise enough food for everyone in the village. Work became more specialized, with nonfarmers trading their goods and services for food.

A Changing Way of Life

Surpluses and specialization led to the growth of villages. Life became more complex in certain villages as they developed. Extra food and other supplies meant that more people could live together. In this way, surpluses encouraged the growth of villages and populations. Surpluses also led to increased trade. People in one village might trade their surplus food for the surplus tools in another village.

Workers became more specialized. Potters, weavers, and other craftspeople often spent years learning their skills. People trained in skills or crafts are called artisans. Carpenters, toolmakers, cloth makers, and potters are all artisans. People with similar skills developed into occupational classes. In this way, specialization led to the development of social classes. A social class is a group of people with similar customs, backgrounds, training, and income, such as farmers, craftspeople, priests, or rulers. As ancient communities grew into larger villages, people felt the need for laws and leadership to keep order and settle disputes. People developed early forms of government—that is, ways of creating order and providing leadership. Early humans made laws to make their communities both safer and more stable.

From Simple to Complex Villages

A complex village had a larger population than a simple village, with people living closer together. The larger population had a greater supply of skills, ideas, and needs. As a result, life in a complex village was more varied and complicated than that in a simple village.

Complex villages were not like the cities of today. Although one of these villages may have had as many as 5,000 people, it would be quite small by today’s standards. However, thousands of years ago, a village with a population of 5,000 would have been very large. Most farming villages had only a few hundred inhabitants.