Evolution and sustainability: gathering the strands for an Anthropocene synthesis

Abstract

How did human societies evolve to become a major force of global change? What dynamics can lead societies on a trajectory of global sustainability? The astonishing growth in human population, economic activity, technological capacity and environmental impact - together known as the Anthropocene - has brought these questions to the fore. In this theme issue, we bring together the major elements of a theory of human evolution and sustainability on Earth. We show how diverse theories and approaches help to understand the past, present and future evolution of the Anthropocene, and discover new opportunities for moving towards sustainability. Collectively, the work provides the basis for an evolutionary synthesis of the human predicament on planet Earth. Positive feedbacks in deep-time transitions of human populations Abrupt and rapid changes in human societies are among the most exciting population phenomena. Human populations tend to show rapid expansions from low to high population density along with increased social complexity in just a few generations. Such demographic transitions appear as a remarkable feature of Homo sapiens population dynamics, most likely fuelled by the ability to accumulate cultural/technological innovations that actively modify their environment. We are especially interested in establishing if the demographic transitions of pre-historic populations show the same dynamic signature of the Industrial Revolution transition (a positive relationship between population growth rates and size). Our results show that population growth patterns across different pre-historic societies were similar to those observed during the Industrial Revolution in developed western societies. These features, which appear to have been operating during most of our recent demographic history from hunter–gatherers to modern industrial societies, imply that the dynamics of cooperation underlay sudden population transitions in human societies. Continuities and discontinuities in the cultural evolution of global consciousness Global consciousness (GC), encompassing cosmopolitan orientation, global orientations (i.e. openness to multicultural experiences) and identification with all humanity, is a relatively stable individual difference that is strongly associated with pro-environmental attitudes and behaviours, less ingroup favouritism and prejudice, and greater pandemic prevention safety behaviours. Little is known about how it is socialized in everyday life. Using stratified samples from six societies, socializing institution factors correlating positively with GC were education, white collar work (and its higher income) and religiosity. However, GC also decreased with increasing age, contradicting a ‘wisdom of elders’ transmission of social learning, and not replicating typical findings that general prosociality increases with age. Longitudinal findings were that empathy-building, network-enhancing elements like getting married or welcoming a new infant, increased GC the most across a three-month interval. Instrumental gains like receiving a promotion (or getting a better job) also showed positive effects. Less intuitively, death of a close-other enhanced rather than reduced GC. Perhaps this was achieved through the ritualized management of meaning where a sense of the smallness of self is associated with growth of empathy for the human condition, as a more discontinuous or opportunistic form of culture-based learning. The Anthropocene condition: evolving through social–ecological transformations Anthropogenic planetary disruptions, from climate change to biodiversity loss, are unprecedented challenges for human societies. Some societies, social groups, cultural practices, technologies and institutions are already disintegrating or disappearing as a result. However, this coupling of socially produced environmental challenges with disruptive social changes—the Anthropocene condition—is not new. From food-producing hunter–gatherers, to farmers, to urban industrial food systems, the current planetary entanglement has its roots in millennia of evolving and accumulating sociocultural capabilities for shaping the cultured environments that our societies have always lived in (sociocultural niche construction). When these transformative capabilities to shape environments are coupled with sociocultural adaptations enabling societies to more effectively shape and live in transformed environments, the social–ecological scales and intensities of these transformations can accelerate through a positive feedback loop of ‘runaway sociocultural niche construction’. Efforts to achieve a better future for both people and planet will depend on guiding this runaway evolutionary process towards better outcomes by redirecting Earth's most disruptive force of nature: the power of human aspirations. To guide this unprecedented planetary force, cultural narratives that appeal to human aspirations for a better future will be more effective than narratives of environmental crisis and overstepping natural boundaries. Reducing global inequality increases local cooperation: a simple model of group selection with a global externality Group-structured models often explain the evolution of prosocial activities in terms of selection acting at both individual and group levels. Such models do not typically consider how individuals' behaviours may have consequences beyond the boundaries of their groups. However, many behaviours affect global environmental variables, including climate change and ecosystem fragility. Against this background, we propose a simple model of multi-level selection in the presence of global externalities. In our model, group members can cooperate in a social dilemma with the potential for group-level benefits. The actions of cooperators also have global consequences, which can be positive (a global good) or negative (a global bad). We use simulations to consider scenarios in which the effects of the global externality either are evenly distributed, or have stronger influences on either the rich or the poor. We find that the global externality promotes the evolution of cooperation only if it either disproportionately benefits the poor or disproportionately reduces the payoffs of the rich. If the global externality primarily harms the poor, it undermines the evolution of prosocial behaviour. Understanding this effect is important given concerns that poorer households are more vulnerable to climate change impacts. Green preferences sustain greenwashing: challenges in the cultural transition to a sustainable future Discussions of the environmental impact that revolve around monetary incentives and other easy-to-measure factors are important, but they neglect culture. Pro-environmental values will be crucial when facing sustainability challenges in the Anthropocene, and demand among green consumers is arguably critical to incentivise sustainable production. However, owing to asymmetric information, consumers might not know whether the premium they pay for green production is well-spent. Reliable monitoring of manufacturers is meant to solve this problem. To see how this might work, we develop and analyse a game theoretic model of a simple buyer–seller exchange with asymmetric information, and our analysis shows that greenwashing can exist exactly because reliable monitoring co-exists with unreliable monitoring. More broadly, promoting pro-environmental values among consumers might even amplify the problem at times because a manufacturer with significant market power can exploit both consumer preferences for sustainability and trustworthy monitoring to gouge prices and in extreme cases green wash in plain sight. We discuss several strategies to address this problem. Promoting accurate beliefs and a large-scale behavioural change based on pro-environmental values might be necessary for a rapid transition to a sustainable future, but recent evidence from the cultural evolution literature highlights many important challenges.