Sumer developed into the first Civilization around 3500 BCE.
During the old Stone Age, people used stone tools. People hunted and gathered for their food. Because of an unreliable supply of food, they lived a nomadic life style. Groups were typically no larger than 20-60 people.
The New Stone Age began about 9000 BCE when people learned to grow crops. People were able to live in one place. Agriculture created a stable supply of food, allowing for the population to increase. Farming villages began arising some even became cities.
Some areas of the world experienced a dramatic shift in their way of life; the development of civilization. These places saw the development of writing,government,job specialization, and