Prehistory began over 2.5 million years ago with the emergence of the first humans and ended around 3500 BC with the development of writing systems. During this time, humans evolved from hunter-gatherers to early agricultural societies. Prehistory is divided into periods including the Palaeolithic, Mesolithic, and Neolithic. In the Palaeolithic, humans lived nomadic lifestyles and created tools from stone, bone, and wood. The Neolithic period saw the development of farming and permanent settlements. Metals like copper, bronze, and iron were introduced and new technologies led to social changes and early trade networks and cities.