The first chapter of Traditions and Encounters sets the stage for the drama of world history by tracing the development of humans from their earliest appearance on earth through the rise of important early civilizations and the development of key institutions and cultural practices. This chapter addresses the physical evolution and migration of the species, the revolutionary transformation from hunting and gathering to sedentary agriculture, the rise of enormously influential complex societies in Mesopotamia along the fertile river valleys of the Tigris and the Euphrates, and the subsequent impact that Mesopotamian societies would have on other cultures in the region. As a result of this dramatic transformation

• An unprecedented population explosion occurred due to the increase in the food supply.
• Humans established permanent settlement in villages and, later, in cities.
• Social classes emerged as the result of labor specialization and the accumulation of wealth. The desire for the more sophisticated goods produced by specialists also helped to stimulate trade with other societies, and greatly expanding intercultural contact.
• Early societies in Mesopotamia developed governmental institutions to provide order and stability and to resolve disputes. These institutions evolved into hereditary kingships and, at times, into empires when states sought to expand their dominion to neighboring lands.
• Mesopotamian societies also developed important cultural traditions including increasingly elaborate religions and a system of writing that would endure for thousands of years.