Toward a theory of punctuated subsistence change

Abstract

Discourse on the origins and spread of domesticated species focuses on universal causal explanations or unique regional or temporal trajectories. Despite new data as to the context and physical processes of early domestication, researchers still do not understand the types of system-level reorganizations required to transition from foraging to farming. Drawing upon dynamical systems theory and the concepts of attractors and repellors, we develop an understanding of subsistence transition and a description of variation in, and emergence of, human subsistence systems. The overlooked role of attractors and repellors in these systems helps explain why the origins of agriculture occurred quickly in some times and places, but slowly in others. A deeper understanding of the interactions of a limited set of variables that control the size of attractors (a proxy for resilience), such as population size, number of dry months, net primary productivity, and settlement fixity, provides new insights into the origin and spread of domesticated species in human economies.complex adaptive systems | subsistence change | origins of agriculture | social-ecological systems R ecent work highlights that the transition from foraging to farming was nonlinear and heterogeneous (e.g., refs. 1-7). That is, rather than an inevitability, early shifts to food production were only one of many possible outcomes that could have been reached for a given set of dynamically interacting social and ecological variables. Although the forager-farmer transition is one of the most fundamental changes in human evolution, our understanding of the forager-farmer transition is theoretically fractious (1,(3)(4)(5)(6), with scholarly discourse dominated by the assumption that the forager adoption of domesticates was driven either by subsistence necessity or because domesticates provided a desirable opportunity or assurance. Given our adaptive flexibility, however, it is clear that both options are possible, depending on the situation. The challenge is distinguishing the contextual settings in which adoptions were linked to necessity versus opportunity. Simply put, there is currently no sufficient theory to explain the nonlinear and contingent worldwide transitions from foraging to farming.In this paper, we use concepts from Dynamical Systems Theory (SI Text S1) to model subsistence variation among contemporary ethnographic groups from an evolutionary perspective. We focus on a critical question: How can researchers use the concepts of attractors and repellors-so integral to understanding many nonlinear dynamical systems-to describe variation in the subsistence strategies of human societies? This framing provides general insights into why transitions from foraging to farming, at a global scale, exhibit nonlinearity and heterogeneity, and why the shift was sometimes gradual, and other times punctuated. Drawing upon comparative ethnographic case studies, we formalize the use of cross-cultural data in a theory-backed methodology to ascertain how the attractor/repel...

Resilience (Republished)

“…The likelihood of such shifts increases with loss of resilience (e.g., Scheffer et al 2001). During the last decades it has become clear that human actions cause such shifts by altering resilience and disturbances (e.g., , Biggs et al 2012b, Schoon and Cox 2012 as is now illustrated from a growing set of examples of both ecosystems and social-ecological systems (Rocha et al 2015) and even largescale reorganizations like historical shifts from foraging to farming (Ullaha et al 2015). The Regime Shifts DataBase provides examples of different types of regime shifts that have been documented.…”

Resilience of small-scale societies’ livelihoods: a framework for studying the transition from food gathering to food production

“…Conversely, have argued that this hyper reliance on empirical data has contributed to the rejection of general explanations on the origins of agriculture (OA) and the consequent loss of theoretically driven hypothesis testing. Moreover, scholars tend to explain this transition either as a necessity, e.g., due to climate change, or as an opportunity, e.g., because domesticates offer more reliable food sources (see as Ullah et al 2015). However, it is becoming clearer that both these mechanisms often acted in concert and at the same time or at different chronological or spatial locations and the challenge is to distinguish between these two occurrences.…”

“…However, it is becoming clearer that both these mechanisms often acted in concert and at the same time or at different chronological or spatial locations and the challenge is to distinguish between these two occurrences. Recent advances in modeling and simulation approaches in archeological research provide an opportunity for a detailed study of both the processes and transitions associated with agricultural production (Allaby et al 2008, van Etten and Hijmans 2010, Ullah et al 2015, and thus offer a formal tool to help close the gap in our understanding of the transition between huntergatherer (HG) and agro-pastoral (AP) societies.…”

Mapping Social Ecological Systems Archetypes

“…This framework has gained empirical support (16) with studies that range from the watershed to national scales in Canada (17,18), Sweden (19,20), Germany (21), and South Africa (22). Similar ordination methods has also been used to study regime shifts from foraging to farming societies in ancient SES (23).…”