Agrarian Civilizations By Josie Hernandez 8000 BCE The worlds population to about 6 million in 8000 BCE 3200 BCE The first civilizations developed at about 3200 BCE in Mesopotamia, in Egypt and Nubia and in the Indus Valley. 3000 BCE The world population went up to 50 million in 3000 BCE 2000 BCE Central America and along the Andes Mountains of South America