Toward a theory of non-linear transitions from foraging to farming

The evolution of agricultural economies requires two processes: (1) the domestication of plants and (2) specialization in agricultural practices at the expense of alternative subsistence pursuits. Yet, in the literature, domestication receives the lion's share of attention while theories of specialization lag behind. In this paper, we integrate ideas from human behavioral ecology (HBE) with tools from dynamical systems theory to study the effects of ecological inheritance on levels of investment in foraging and farming. Ecological inheritance is an outcome of niche construction and our study provides a formal link between foraging theory and niche construction. Our analysis of a dynamic model of foraging and farming illustrates that the optimal allocation of effort to foraging and farming can lead to the emergence of multiple stable states. The consequence of this is that low-level farming optimizes subsistence (e.g., minimizing the effort required to meet a subsistence goal) in a forager-resource system over a few years, but makes the whole system vulnerable to punctuated change over decades due to rare events. We use the insights of our model to propose a general ecological framework to explain the evolution and diversity of transitions from foraging to farming.