Abstract
The food-producing revolution in southwestern Asia is here viewed not as the brilliant invention of one group or the product of a single environmental zone, but as the result of a long process of changing ecological relationships between groups of men (living at varying altitudes and in different environmental settings) and the locally available plants and animals which they had been exploiting on a shifting, seasonal basis. In the course of making available to all groups the natural resources of every environmental zone, man had to remove from their natural contexts a number of hard-grained grasses and several species of ungulates. These species, as well as obsidian and native copper, were transported far from the biotopes or "niches" in which they had been at home. Shielded from natural selection by man, these small breeding populations underwent genetic change in the environment to which they had been transplanted, and favorable changes were emphasized by the practices of the early planter or herder. Successful cultivation seems to have intensified exchanges of natural resources and cultivars between groups, and there are hints that the diversity of environments made village specialization in certain commodities the best means of adapting to the area. We have suggestive evidence that by 4000 B.C. the re-distributive economy had produced regional temple-and-market towns which regulated the produce of a symbiotic network of agriculturists engaged in intensive irrigation, transhumant herders, and perhaps even traders who dealt in obsidian, copper, salt, asphalt, fish, and regional fruits.