By 7000 B.C.E. or so, some agricultural villages in the Fertile Crescent may have had as many as ten thousand residents. One of the best known of these, Çatal Hüyük in what is now Turkey, shows evidence of trade as well as specialization of labor. Çatal Hüyük’s residents made textiles, pots, figurines, baskets, carpets, copper and lead beads, and other goods, and decorated their houses with murals showing animal and human figures. They gathered, sharpened, and polished obsidian, a volcanic rock that could be used for knives, blades, and mirrors, and then traded it with neighboring towns, obtaining seashells and flint. From here the obsidian was exchanged still farther away, for Neolithic societies slowly developed local and then regional networks of exchange and communication.

Among the goods traded in some parts of the world was copper, which people hammered into shapes for jewelry and tools. By about 5500 B.C.E., people in the Balkans had learned that copper could be extracted from ore by heating it in a smelting process. Smelted copper was poured into molds and made into spear points, axes, chisels, beads, and other objects. Pure copper is soft, but through experimentation artisans learned that it would become harder if they mixed it with other metals during heating, creating an alloy called bronze.

Because it was stronger than copper, bronze had a far wider range of uses, so much so that later historians decided that its adoption marked a new period in human history: the Bronze Age. The Bronze Age began about 3000 B.C.E., and by about 2500 B.C.E., bronze technology was having an impact in many parts of the world. The end of the Bronze Age came with the adoption of iron technology, a development that began around 1200 B.C.E. (see Chapter 2).

Objects were not the only things traded over increasingly long distances during the Neolithic period, for people also carried ideas as they traveled. Knowledge about the seasons and the weather was vitally important for those who depended on crop raising, and agricultural peoples in many parts of the world began to calculate recurring patterns in the world around them, slowly developing calendars.

The rhythms of the agricultural cycle and patterns of exchange also shaped religious beliefs and practices. In many places multiple gods came to be associated with patterns of birth, growth, death, and regeneration in a system known as polytheism. Like humans, the gods came to have a division of labor and a social hierarchy.