History of the World

History of the World
Homo sapiens first arose on the Earth between 400 and 250 thousand years ago during the Paleolithic period. This occurred after a long period of evolution. Ancestors of humans had been using simple tools for many millennia, but as time progressed, tools became far more refined and complex. At some point humans had begun using fire for heat and for cooking. Humans also developed language sometime during the Paleolithic. During this period all humans lived as hunter-gatherers who were generally nomadic
Neolithic

A major change occurred around 8,500 BC in the Fertile Crescent area of the Middle East when humans adopted agriculture. Soon after, it was developed independently and spread to China, Egypt, and the Indus Valley. Several millennia later, agriculture developed in Africa and in the Americas. Some areas such as Australia did not use agriculture until relatively modern times, although in some areas of Australia, fish-based farming was practiced by the aboriginal population which is thought to have arrived 50,000 years before the present.
Agriculture led to several major changes. It allowed far larger population densities. It also created, and allowed for the storage, of food surpluses that could support people not directly involved in food production. The development of agriculture allowed the creation of the first cities.
The development of cities has led to what has been called civilization. First in the river valleys of the Tigris and Euphrates and soon after along the Nile, Yangtze, and Indus evidence of elaborate cities with merchants and rulers is found. At this same time developments such as writing, currency, and extensive trade were introduced.

Bronze and Iron Age
The agricultural settlements had until this time been almost completely dependent on stone tools. In Eurasia around 3000 BC copper and bronze tools, decorations, and weapons began to become commonplace. Some areas of the world, including all of the Americas,...