Trading public goods stabilizes interspecific mutualism (original) (raw)
Related papers
Theoretical Population Biology, 2004
We analyse the evolution of the assortment of encounters through active choice of companions among individuals that interact cooperatively in a situation of mutual benefit. Using a simple mathematical model, we show that mutual benefit can favour the evolution of a preference to interact with individuals that are similar to themselves with respect to an arbitrary tag even when both the preference and the tag depend on two independent and unlinked genes. Two necessary requisites to obtain this result are: (i) a small population or a large subdivided metapulation and (ii) an asymmetry between partners in such a way that one of them (donor) proposes the cooperation and elects the partner, whereas the other (receiver) never rejects the offer. We also show that mutual benefit can be the starting point for the evolution of altruistic behaviours as long as there are preferential interactions. This requires that the tag used in the election of partners is the altruistic or selfish behaviour itself.
The evolution of cooperation and diversity by integrated indirect reciprocity
arXiv (Cornell University), 2023
Indirect reciprocity is one of the major mechanisms for the evolution of cooperation in human societies. There are two types of indirect reciprocity: upstream and downstream. Cooperation in downstream reciprocity follows the pattern, 'You helped someone, and I will help you'. The direction of cooperation is reversed in upstream reciprocity, which instead follows the pattern, 'You helped me, and I will help someone else'. In reality, these two types of indirect reciprocity often occur in combination. However, upstream and downstream reciprocity have mostly been studied theoretically in isolation. Here, we propose a new model that integrates both types. We apply the standard giving-game framework of indirect reciprocity and analyze the model by means of evolutionary game theory. We show that the model can result in the stable coexistence of altruistic reciprocators and free riders in well-mixed populations. We also found that considering inattention in the assessment rule can strengthen the stability of this mixed equilibrium, even resulting in a global attractor. Our results indicate that the cycles of forwarding help and rewarding help need to be established for creating and maintaining diversity and inclusion in a society.
The evolution of cooperation by social exclusion
Proceedings of the Royal Society B: Biological Sciences, 2012
The exclusion of freeriders from common privileges or public acceptance is widely found in the real world. Current models on the evolution of cooperation with incentives mostly assume peer sanctioning, whereby a punisher imposes penalties on freeriders at a cost to itself. It is well known that such costly punishment has two substantial difficulties. First, a rare punishing cooperator barely subverts the asocial society of freeriders, and second, natural selection often eliminates punishing cooperators in the presence of non-punishing cooperators (namely, ‘second-order’ freeriders). We present a game-theoretical model of social exclusion in which a punishing cooperator can exclude freeriders from benefit sharing. We show that such social exclusion can overcome the above-mentioned difficulties even if it is costly and stochastic. The results do not require a genetic relationship, repeated interaction, reputation or group selection. Instead, only a limited number of freeriders are req...
Symbiotic behaviour in the public goods game with altruistic punishment
Journal of Theoretical Biology, 2021
Finding ways to overcome the temptation to exploit one another is still a challenge in behavioural sciences. In the framework of evolutionary game theory, punishing strategies are frequently used to promote cooperation in competitive environments. Here, we introduce altruistic punishers in the spatial public goods game. This strategy acts as a cooperator in the absence of defectors, otherwise it will punish all defectors in their vicinity while bearing a cost to do so. We observe three distinct behaviours in our model: i) in the absence of punishers, cooperators (who don't punish defectors) are driven to extinction by defectors for most parameter values; ii) clusters of punishers thrive by sharing the punishment costs when these are low iii) for higher punishment costs, punishers, when alone, are subject to exploitation but in the presence of cooperators can form a symbiotic spatial structure that benefits both. This last observation is our main finding since neither cooperation nor punishment alone can survive the defector strategy in this parameter region and the specificity of the symbiotic spatial configuration shows that lattice topology plays a central role in sustaining cooperation. Results were obtained by means of Monte Carlo simulations on a square lattice and subsequently confirmed by a pairwise comparison of different strategies' payoffs in diverse group compositions, leading to a phase diagram of the possible states.
Resource abundance promotes the evolution of public goods cooperation
Proceedings of the 12th annual conference on Genetic and evolutionary computation - GECCO '10, 2010
Understanding the evolution of cooperation as part of an evolutionary stable strategy (ESS) is a difficult problem that has been the focus of much work. The associated costs of cooperation may lower the fitness of an organism below that of its non-cooperating counterpart, allowing the more fit organism to persist and outcompete the cooperator. Insight into these behaviors can help provide a better understanding of many aspects of the natural world, as well as provide future avenues for fighting disease. In this study, we use digital evolution to examine how the abundance of a required resource affects the cooperative production of a public good in an adverse environment. Evolutionary computation is an excellent tool for examining these problems, as it offers researchers complete access to organisms and total control over their environment. We find that stable cooperation can occur in otherwise competitive environments at discrete levels corresponding to the availability of a required resource. When resource levels are low, organisms focus solely on competitive behaviors. However, once resource levels cross a critical threshold, cooperation persists in populations. Further, this cooperation occurs in patches, where it is most likely to benefit relatives. Finally, we find that in some cases this cooperative behavior allows organisms to increase their competitive abilities as well.
Economic Game Theory for Mutualism and Cooperation
We review recent work at the interface of economic game theory and evolutionary biology that provides new insights into the evolution of partner choice, host sanctions, partner fidelity feedback, and public goods. (1) The theory of games with asymmetric information shows that the right incentives allow hosts to screen-out parasites and screen-in mutualists, explaining successful partner choice in the absence of signalling. Applications range from ant-plants to microbiomes. (2) Contract theory distinguishes two longstanding but weakly differentiated explanations of host response to cheaters: host sanctions and partner fidelity feedback. Host traits that selectively punish misbehaving symbionts are parsimoniously interpreted as pre-adaptations. Yucca-moth and legume-rhizobia mutualisms are argued to be examples of partner fidelity feedback. (3) The theory of public goods shows that cooperation in multi-player interactions can evolve in the absence of assortment, in one-shot social dilemmas among non-kin. Applications include alarm calls in vertebrates and exoenzymes in microbes.
2009
An oft-cited and robust result from Public Goods Game experiments is that, when subjects start playing, the aggregate level of contributions is significantly different from zero. At the same time, a sizeable proportion of players free ride from the outset. Behavioural economics has persuasively shown that these laboratory findings are compatible with the presence of motivationally heterogeneous agents, displaying both standard, self-centred preferences and non-standard, interdependent preferences. However, at the theoretical level, economists would prefer to account for motivational heterogeneity endogenously, instead of simply assuming it from the outset. Our work provides such endogenisation, by assuming that social evolution is driven by material payoffs only. By separately focusing on different types of 'experimentally salient' pro-social players (such as Reciprocators, Strong Reciprocators and Altruists), we are able to shed light -to our knowledge, for the first time, within the public good framework -on the evolutionary stability of two-type populations consisting of positive proportions of both 'nice' and 'mean' guys.
Economic contract theory tests models of mutualism
Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host–symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume–rhizobia and yucca–moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.
Behaviour, 2016
Despite the fact that most models of cooperation assume equal outcomes between individuals, in real life it is likely rare that this is the case. Does it make a difference for our understanding of the evolution of cooperation? Following a taxonomy of cooperation concepts that focuses on costs and benefits, we explore this question by considering the degree to which inequity aversion may provide one mechanism to stabilize cooperation. We suggest a key role for inequity aversion in some contexts in both biological markets and direct reciprocity, and highlight the potentially unique role of positive inequity aversion for human reputation games. Nevertheless, a key challenge is to determine how different animal species perceive the payoff structure of their interactions, how they see their interaction with their partners, and the degree to which simpler mechanisms, like contrast effects or the associative learning seen in optimal foraging, may produce similar outcomes.
Let the right one in: a microeconomic approach to partner choice in mutualisms
One of the main problems impeding the evolution of cooperation between species is partner choice. When information is asymmetric (the quality of the potential partners is known only to themselves), an interaction with high-quality partners can be established if they can signal their quality. If signaling is not possible, or if hosts cannot actively choose, it may seem that partner choice is not possible. Many mutualisms, however, exist without signaling, and the mechanisms by which hosts might select the right partners are unclear. For example, can an animal exclude parasitic bacteria from its gut, and can a plant favor colonization by beneficial ants, bacteria, or fungi? Here we propose a very general mechanism of partner choice, ‘screening,’ that is taken from the economic theory of mechanism design. If a host evolves an appropriate entry cost for potential partners, such that the ability to pay the cost is correlated with their quality as symbionts, then only high-quality partners will find it profitable to accept the interaction, and low-quality partners will screen themselves out of the interaction, or not evolve to colonize the host. Several types of biological symbioses are good candidates for screening, including bobtail squid, ant-plants, gut microbiomes, and the many animal and plant species that produce reactive oxygen species while paradoxically also hosting beneficial bacteria. We describe a series of diagnostic tests for screening. Screening games can apply to the difficult cases where by-products, partner fidelity feedback, or host sanctions do not apply, therefore explaining the evolution of mutualism in systems that are not repeated games or vertically transmitted, where it is impossible for potential symbionts to signal their cooperativeness beforehand, and where the host does not punish symbiont misbehavior.