The Origins of Specialized Nomadic Pastoralism: A Systemic Model

Abstract

A model is presented which describes the transition from mixed rainfall-dependent agriculture with animal husbandry to specialized modes of production based upon irrigated agriculture and nomadic pastoralism. This model emphasizes selective pressures for mixed farming before irrigation agriculture had expanded in the arid alluvial zones of Mesopotamia, and selective pressures for specialization after irrigation agriculture had become established in that zone. It goes on to describe dynamic interaction between specialized groups once such specialization has become institutionalized.