The importance of mechanisms for the evolution of cooperation

Abstract

Studies aimed at explaining the evolution of phenotypic traits have often solely focused on fitness considerations, ignoring underlying mechanisms. In recent years, there has been an increasing call for integrating mechanistic perspectives in evolutionary considerations, but it is not clear whether and how mechanisms affect the course and outcome of evolution. To study this, we compare four mechanistic implementations of two well-studied models for the evolution of cooperation, the Iterated Prisoner's Dilemma (IPD) game and the Iterated Snowdrift (ISD) game. Behavioural strategies are either implemented by a 1 : 1 genotype-phenotype mapping or by a simple neural network. Moreover, we consider two different scenarios for the effect of mutations. The same set of strategies is feasible in all four implementations, but the probability that a given strategy arises owing to mutation is largely dependent on the behavioural and genetic architecture. Our individual-based simulations show that this has major implications for the evolutionary outcome. In the ISD, different evolutionarily stable strategies are predominant in the four implementations, while in the IPD each implementation creates a characteristic dynamical pattern. As a consequence, the evolved average level of cooperation is also strongly dependent on the underlying mechanism. We argue that our findings are of general relevance for the evolution of social behaviour, pleading for the integration of a mechanistic perspective in models of social evolution.

The evolution of cognitive mechanisms in response to cultural innovations

“…Thus, to consider how culture shapes the evolution of cognition, we must explain how such mechanisms work and how they can be modified by natural selection. The importance of using mechanistic models in the study of behavioral evolution is increasingly recognized (65)(66)(67)(68), but most attempts to integrate evolutionary theory and cognition are still based on modeling the evolution of learning rules that are far too simple to capture complex cognition (69)(70)(71)(72)(73)(74). To understand how culture shapes the evolution of cognitive mechanisms, such as those serving imitation, theory of mind, or language acquisition, it is necessary to have models that explain how such mechanisms work and how they could evolve.…”

Negotiation and appeasement can be more effective drivers of sociality than kin selection

“…Alternatively, cooperation can arise when individuals respond to the actions of others [4 -6]. Responsive strategies can favour cooperation through a range of different mechanisms; for example, when individuals reciprocate help received from others [4,5], when individuals choose their interaction partner based on its previous actions [7][8][9] or when individuals punish uncooperative partners [10]. Genetic assortment and responsive strategies are central to the two most prominent frameworks for explaining the evolution of cooperative behaviours: kin selection theory [1,2] and the theory of reciprocal altruism [5,11].…”

Introduction to Symposium: The Developmental and Proximate Mechanisms Causing Individual Variation in Cooperative Behavior

“…Today, this is often studied under the theme of consistent differences in behavior (i.e., animal personality, temperament: Réale et al 2007) or correlations among different behaviors (i.e., behavioral syndromes: Sih et al 2004). Theory suggests that individual-variation in cooperative behavior or social responsiveness plays a primary role not only in determining if cooperation evolves, but also the degree of cooperation that evolves (McNamara et al 2004(McNamara et al , 2008McNamara and Leimar 2010;Johnstone and Manica 2011;van den Berg et al 2015). That is, the presence of individual variation in behavior makes the evolution of cooperation more likely and increases the overall level of cooperation among individuals (Wolf and Krause 2014).…”

“…Theoretical models such as those based on reciprocity (Trivers 1971;Axelrod and Hamilton 1981) or kin selection (Hamilton 1964) predict the conditions under which cooperation is likely to evolve through natural selection. Although these traditional models have resulted in productive research paradigms that have shaped the formal study of animal behavior for >50 years, more recent models suggest that the evolution of cooperation is also heavily influenced by the degree of individual variation in cooperative behavior (McNamara et al 2004(McNamara et al , 2008McNamara and Leimar 2010;Johnstone and Manica 2011;van den Berg et al 2015), as well as by their underlying developmental (i.e., how the current or past environment alters behavior) and proximate mechanisms (i.e., control mechanisms such as the genomic or physiological causes of the behavior) (van den Berg and Weissing 2015).…”