The formative period for civilized humanity on Old Earth, from about 7000 BT (4000 b.c.e.), when the first societies transformed by agricultural technologies appeared, to about 270 BT (1700 b.c.e.) when the first societies transformed by Industrial technologies arose, bringing about the Industrial Age.
Agricultural technologies permitted humans to harness a significant fraction of the biosphere's output through the use of domesticated animal and plant species. The resulting energy subsidy supported unprecedented population densities and societal complexity. Cities, written records, organized religions, monetary systems, formal governments, armies, bureaucracies, and the other trappings of civilization were the result. These led in turn to the discovery of the more potent energy sources that permitted the Industrial Age.
Subdivisions of the Agricultural Age are sometimes named for notable technologies of the period (Iron Age, Bronze Age, Neolithic). The term "Agricultural Age" may also be used for the characteristic technologies of this period, for Terragens who live at a comparable level of technology, or for similar periods in the development of xenosophont species.
Agricultural Revolution - Text by M. Alan Kazlev; some additions by Stephen Inniss The first stage of the Kardashev Type 0 Civilization, in which people move away from living as bands of gatherers and hunters, and begin to cluster into villages and develop culture. Cultivation of crops and tending of livestock enables a much higher population density than is possible with nomadic tribalism, and also allows specialization of labor, the development of skills and urbanization, writing, priesthood, slaveholding, taxes, a standing army, and other aspects of civilized culture.