The next stage of development, the Neolithic, is marked by the invention and almost universal adoption of four important new features: agriculture, domesticated animals, pottery, and polished (instead of chipped) stone tools. These changes and the results which flowed from them were revolutionary. Man ceased being a nomad, eternally following his food supply, and became a sedentary being, residing and growing his food in one spot. He now had an assured food supply to carry over lean seasons and this led to a great increase in the population, in most of the formerly inhabited areas, and the opening to settlement of new areas, such as loess lands of Asia and Europe. The altered conditions likewise made possible the accumulation of possessions, the creation and satisfaction of new needs, the leisure for invention and speculation, the growth of large communities and cities, the development of more complex social organization, and in fact all the progress that has taken place since that time.
The four new culture traits which characterize the Neolithic were not necessarily originated at the same time and in the same place, and there is some evidence to indicate that there may have been an early stage, with primitive hoe agriculture and the pig. as a domestic animal, before the advent of the Full Neolithic, with oxen, sheep, and plow agriculture. However, there is good reason to believe that Neolithic culture as a whole was developed in one general center and spread from there in successive waves to the ends of Asia, Africa, and Europe, but not, in any significant sense, to the New World. This original center was probably western Asia, for the wild relatives of the cereals and animals that were first domesticated have their home there, and it was the region in which the higher culture or civilization which the Neolithic discoveries made possible was first developed. The earliest remains of Neolithic culture which have yet been found are in Mesopotamia, Syria, Palestine, and Egypt. They represent a fully developed stage of the culture, with wheat and barley in cultivation and cattle, sheep, goats, and pigs as domesticated animals. The date of these remains is considered to be about 4000 B.c.-a period immediately prior to the first use of copper.
Neolithic remains of a much more primitive character have been found in other parts of the Old World, but they are all apparently later than this in date. The first traces of the Neolithic that have been found in Europe are apparently not older than 3000 or 2500 B.C., and Neolithic culture did not begin in many parts of Asia and Africa until much later still.