We are not sufficiently amazed that societies engaged in foraging have survived into the present, overlapping with the rise of academic anthropology and evolutionary inquiries into our past. Agricultural societies relying nearly exclusively on domesticated animals and plants have been only partially successful in supplanting populations engaged in foraging for non-domesticates, even in contexts where foragers had access to domesticated cultivars for thousands of years. We advance seven behavioral ecology reasons that foragers endure, that the
transition from food gathering to food production either was not initiated, was initiated and resulted in a stable mixed-economy, or was initiated and then reversed. They include: 1) structural impediments to a full commitment to farming, like mobility; 2) comparable relative profitability of individual tasks associated with foraging and cultivation ensuring that they mix without dramatic impacts on the foraging economy; 3) fluctuating marginal reversals of selection; 4) population ecology constraints on foraging intensification; 5) barter and trade; 6) discounting of delayed return subsistence activities; and, 7) challenges to successful agricultural risk management. Prehistoric societies that fully and irreversibly made the evolutionary transition to horticulture/agriculture were either unaffected by such impediments or happened upon or devised solutions to them. Our hypotheses illustrate concepts such as opportunity costs, marginal advantage, discounting and risk, basic to the theoretical analysis of any evolutionary transformation.
