Our fragile future under the cumulative cultural evolution of two technologies

Abstract

We derive and analyse a model with unusual features characterizing human activities over the long-run. First, human population dynamics draw heavily on consumer–resource modelling in ecology in that humans must consume biological resources to produce new humans. Second, the model also draws heavily from economic growth theory in that humans do not simply consume biological resources; they also produce the resources they consume. Finally, humans use two types of technology. Consumption technology affects the rate at which humans can extract resources. Production technology controls how effectively humans convert labour into new resources. The dynamics of both types of technology are subject to cumulative cultural evolutionary processes that allow both technological progress and regress. The resulting model exhibits a wide range of dynamical regimes. That said, the system is routinely sensitive to initial conditions, with wildly different outcomes given the same parameter values. Moreover, the system exhibits a basic fragility in the sense that human activities often lead to the endogenous extinction of the human species. This can happen gently, or it can follow periods of explosive human activity with super-exponential growth that ends in collapse. This article is part of the theme issue ‘Evolution and sustainability: gathering the strands for an Anthropocene synthesis’.

Evolution and sustainability: gathering the strands for an Anthropocene synthesis

“…Comparing demographic patterns of prehistoric populations in regions around the world, they find reproduction curves and population signatures that match the more recent population explosion of many industrialized countries. The authors characterize this effect as resulting from the positive feedback between evolving production technology and population size, paralleling the modelled dynamics of Efferson et al [93]. The congruence between these theoretical and empirical findings are notable.…”

“…The authors characterize this effect as resulting from the positive feedback between evolving production technology and population size, paralleling the modelled dynamics of Efferson et al. [93]. The congruence between these theoretical and empirical findings are notable.…”

“…Three contributions in this issue further explore the role of these positive feedbacks in creating the Anthropocene. Efferson et al [93] explore the behaviour of a dynamical model with two types of technologies subjected to cultural evolution: one that expands the regular carrying capacity of resources relevant to humans ( production technology) and one that optimizes the efficiency of their accessibility for human consumption (consumption technology). They find that the model produces a wide variety of dynamics and exhibits extreme sensitivity to initial conditions ( path dependency), and they observe cycles of super-exponential growth and collapse.…”

Agentic processes in cultural evolution: relevance to Anthropocene sustainability

“…Peter Turchin [78] has used coupled differential equation models of class-stratified societies to understand the rise and fall of political discord. Efferson et al [65] introduce a model that blends elements of ecology, economics and cultural evolution. These models roughly fit the empirical data.…”

“…The more complex models introduced by Efferson et al . [65] exhibit a wide range of behaviour depending on parameter values and initial conditions. Notably, the commonest stable state is a ‘post human’ equilibrium in which humans and their culture disappear.…”