scholarly journals Mobility can promote the evolution of cooperation via emergent self-assortment dynamics

2017 ◽  
Author(s):  
Jaideep Joshi ◽  
Iain D Couzin ◽  
Simon A Levin ◽  
Vishwesha Guttal
Keyword(s):  
Cooperative Interaction ◽  
Evolution Of Cooperation ◽  
Environmental Forcing ◽  
Personal Cost ◽  
Differential Adhesion ◽  
Oscillatory Pattern ◽  
Population Structures ◽  
Limited Dispersal ◽  
Selection Framework ◽  
Costly Traits

AbstractThe evolution of costly cooperation, where cooperators pay a personal cost to benefit others, requires that cooperators interact more frequently with other cooperators. This condition, called positive assortment, is known to occur in spatially-structured viscous populations, where individuals typically have low mobility and limited dispersal. However many social organisms across taxa, from cells and bacteria, to birds, fish and ungulates, are mobile, and live in populations with considerable inter-group mixing. In the absence of information regarding others’ traits or conditional strategies, such mixing may inhibit assortment and limit the potential for cooperation to evolve. Here we employ spatially-explicit individual-based evolutionary simulations to incorporate costs and benefits of two coevolving costly traits: cooperative and local cohesive tendencies. We demonstrate that, despite possessing no information about others’ traits or payoffs, mobility (via self-propulsion or environmental forcing) facilitates assortment of cooperators via a dynamically evolving difference in the cohesive tendencies of cooperators and defectors. We show analytically that this assortment can also be viewed in a multilevel selection framework, where selection for cooperation among emergent groups can overcome selection against cooperators within the groups. As a result of these dynamics, we find an oscillatory pattern of cooperation and defection that maintains cooperation even in the absence of well known mechanisms such as kin interactions, reciprocity, local dispersal or conditional strategies that require information on others’ strategies or payoffs. Our results offer insights into differential adhesion based mechanisms for positive assortment and reveal the possibility of cooperative aggregations in dynamic fission-fusion populations.Author SummaryCooperation among animals is ubiquitous. In a cooperative interaction, the cooperator confers a benefit to its partner at a personal cost. How does natural selection favour such a costly behaviour? Classical theories argue that cooperative interactions among genetic relatives, reciprocal cooperators, or among individuals within groups in viscous population structures are necessary to maintain cooperation. However, many organisms are mobile, and live in dynamic (fission-fusion) groups that constantly merge and split. In such populations, the above mechanisms may be inadequate to explain cooperation. Here, we develop a minimal model that explicitly accounts for mobility and cohesion among organisms. We find that mobility can support cooperation via emergent dynamic groups, even in the absence of previously known mechanisms. Our results may offer insights into the evolution of cooperation in animals that live in fission fusion groups, such as birds, fish or mammals, or microbes living in turbulent media, such as in oceans or in the bloodstreams of animal hosts.

scholarly journals The Evolution of Cooperation by the Hankshaw Effect

2015 ◽  
Author(s):  
Sarah P Hammarlund ◽  
Brian D Connelly ◽  
Katherine J Dickinson ◽  
Benjamin Kerr
Keyword(s):  
Cooperative Behavior ◽  
Active Form ◽  
Evolution Of Cooperation ◽  
Genetic Hitchhiking ◽  
Agent Based ◽  
Natural Systems ◽  
Personal Cost ◽  
Stressful Environment ◽  
Competitive Disadvantage ◽  
Limited Dispersal

The evolution of cooperation—costly behavior that benefits others—faces one clear obstacle. Namely, cooperators are always at a competitive disadvantage relative to defectors, individuals that reap the same social benefits, but evade the personal cost. One solution to this problem involves genetic hitchhiking, where the allele encoding cooperative behavior becomes linked to a beneficial mutation. While traditionally seen as a passive process driven purely by chance, here we explore a more active form of hitchhiking. Specifically, we model hitchhiking in the context of adaptation to a stressful environment by cooperators and defectors with spatially limited dispersal. Under such conditions, clustered cooperators reach higher local densities, thereby experiencing more opportunities for mutations than defectors. Thus, the allele encoding cooperation has a greater probability of hitchhiking with alleles conferring stress adaptation. We label this probabilistic enhancement the "Hankshaw effect" after the character Sissy Hankshaw, whose anomalously large thumbs made her a singularly effective hitchhiker. Using an agent-based model, we demonstrate that there exists a broad set of conditions allowing the evolution of cooperation through the Hankshaw effect. We discuss the feasibility of our theoretical assumptions for natural systems, not only for the case of cooperation, but also for other costly social behaviors such as spite. The primary elements of our model, including genetic hitchhiking and population structure, have been discussed separately in previous models exploring the evolution of cooperation. However, the combination of these elements has not been appreciated as a solution to the problem of cooperation.

scholarly journals Evolution of cooperation: The analysis of the case wherein a different player has a different benefit and a different cost

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Shun Kurokawa
Keyword(s):  
Natural Selection ◽  
Prisoner's Dilemma ◽  
Prisoner’S Dilemma ◽  
Evolution Of Cooperation ◽  
Cost Ratio ◽  
Personal Cost ◽  
Model Setting

The existence of cooperation demands explanation in terms of natural selection. Prisoner’s dilemma is a framework often used when studying the evolution of cooperation. In prisoner’s dilemma, most previous studies consider the situation wherein an individual who cooperates will give an opponent an amount b at a personal cost of c, where b > c > 0 while an individual who defects will give nothing. This model setting is convenient; however, previous studies have not considered the case wherein a different player has a different benefit and different cost while in reality, it is natural to consider that a different player has a different benefit and different cost. Here, we raise the following question: Taking that a different individual has a different benefit and a different cost into consideration, what strategy is likely to evolve? In this paper, we focus on the direct reciprocity and analyze the case wherein a different player has a different benefit and a different cost. We obtain the condition for the evolution in the general case. And in addition, we have revealed that under a specific condition as the interaction repeats longer and the benefit-to-cost ratio is larger and the cooperating probability is more sensitive to the benefit the opponent provides, the establishment of cooperation is more likely.

scholarly journals Ordering structured populations in multiplayer cooperation games

2015 ◽  
Author(s):  
Jorge Peña ◽  
Bin Wu ◽  
Arne Traulsen
Keyword(s):  
Population Structure ◽  
Spatial Structure ◽  
Structured Populations ◽  
Evolution Of Cooperation ◽  
Multiplayer Games ◽  
Spatial Games ◽  
Population Structures ◽  
Single Structure ◽  
Containment Order ◽  
Update Rules

AbstractSpatial structure greatly affects the evolution of cooperation. While in two-player games the condition for cooperation to evolve depends on a single structure coefficient, in multiplayer games the condition might depend on several structure coefficients, making it difficult to compare different population structures. We propose a solution to this issue by introducing two simple ways of ordering population structures: the containment order and the volume order. If population structure 𝒮1 is greater than population structure 𝒮2 in the containment or the volume order, then 𝒮1 can be considered a stronger promoter of cooperation. We provide conditions for establishing the containment order, give general results on the volume order, and illustrate our theory by comparing different models of spatial games and associated update rules. Our results hold for a large class of population structures and can be easily applied to specific cases once the structure coefficients have been calculated or estimated.

scholarly journals Evolution of cooperation in an epithelium

2019 ◽  
Vol 16 (152) ◽  
pp. 20180918 ◽  
Author(s):  
Jessie Renton ◽  
Karen M. Page
Keyword(s):  
Social Interactions ◽  
Voronoi Tessellation ◽  
Evolutionary Game ◽  
Cellular Level ◽  
Structured Populations ◽  
Evolution Of Cooperation ◽  
Animal Kingdom ◽  
Population Structures ◽  
Fixation Probabilities ◽  
Evolutionary Graph Theory

Cooperation is prevalent in nature, not only in the context of social interactions within the animal kingdom but also on the cellular level. In cancer, for example, tumour cells can cooperate by producing growth factors. The evolution of cooperation has traditionally been studied for well-mixed populations under the framework of evolutionary game theory, and more recently for structured populations using evolutionary graph theory (EGT). The population structures arising due to cellular arrangement in tissues, however, are dynamic and thus cannot be accurately represented by either of these frameworks. In this work, we compare the conditions for cooperative success in an epithelium modelled using EGT, to those in a mechanical model of an epithelium—the Voronoi tessellation (VT) model. Crucially, in this latter model, cells are able to move, and birth and death are not spatially coupled. We calculate fixation probabilities in the VT model through simulation and an approximate analytic technique and show that this leads to stronger promotion of cooperation in comparison with the EGT model.

scholarly journals The early evolution of cooperation in humans. On cheating, group identity and group size

Behaviour ◽  
2016 ◽  
Vol 153 (9-11) ◽  
pp. 1247-1266 ◽  
Author(s):  
T. Czárán ◽  
Duur K. Aanen
Keyword(s):  
Group Size ◽  
Low Frequency ◽  
Evolution Of Cooperation ◽  
Spatially Explicit ◽  
Group Identities ◽  
Limited Dispersal ◽  
Group Members ◽  
Explicit Simulation ◽  
Group Diversity ◽  
Large Groups

The evolution of cooperation is difficult to understand, because cheaters — individuals who profit without cooperating themselves — have a benefit in interaction with cooperators. Cooperation among humans is even more difficult to understand, because cooperation occurs in large groups, making cheating a bigger threat. Restricting cooperation to members of one’s own group based on some tag-based recognition of non-group members (allorecognition) has been shown to stabilise cooperation. We address how spatial structure and group size affect the opportunities for cheating such tag-based cooperation in a spatially explicit simulation. We show that increased group diversity, under conditions of limited dispersal, reduces the selective opportunities for cheaters. A small number can already be sufficient to keep cheating at a low frequency. We discuss how marginal additional benefits of increased group size, above the benefits of local cooperation, can provide the selective pressure to reduce the number of group identities and discuss possible examples.

scholarly journals The evolution of cooperative breeding in birds: kinship, dispersal and life history

2009 ◽  
Vol 364 (1533) ◽  
pp. 3217-3227 ◽  
Author(s):  
Ben J. Hatchwell
Keyword(s):  
Life History ◽  
Cooperative Breeding ◽  
Family Formation ◽  
Breeding Systems ◽  
Evolution Of Cooperation ◽  
Social Species ◽  
Limited Dispersal ◽  
Kin Structure ◽  
Level I ◽  
Population Viscosity

The evolution of cooperation among animals has posed a major problem for evolutionary biologists, and despite decades of research into avian cooperative breeding systems, many questions about the evolution of their societies remain unresolved. A review of the kin structure of avian societies shows that a large majority live in kin-based groups. This is consistent with the proposed evolutionary routes to cooperative breeding via delayed dispersal leading to family formation, or limited dispersal leading to kin neighbourhoods. Hypotheses proposed to explain the evolution of cooperative breeding systems have focused on the role of population viscosity, induced by ecological/demographic constraints or benefits of philopatry, in generating this kin structure. However, comparative analyses have failed to generate robust predictions about the nature of those constraints, nor differentiated between the viscosity of social and non-social populations, except at a coarse level. I consider deficiencies in our understanding of how avian dispersal strategies differ between social and non-social species, and suggest that research has focused too narrowly on population viscosity and that a broader perspective that encompasses life history and demographic processes may provide fresh insights into the evolution of avian societies.

scholarly journals Parent-preferred dispersal promotes cooperation in structured populations

2019 ◽  
Vol 286 (1895) ◽  
pp. 20181949 ◽  
Author(s):  
Xiaojie Chen ◽  
Åke Brännström ◽  
Ulf Dieckmann
Keyword(s):  
Pairwise Comparison ◽  
Small World ◽  
Structured Populations ◽  
Evolution Of Cooperation ◽  
Pair Approximation ◽  
Scale Free ◽  
Scale Free Networks ◽  
Different Types ◽  
Population Structures ◽  
Update Rules

Dispersal is a key process for the emergence of social and biological behaviours. Yet, little attention has been paid to dispersal's effects on the evolution of cooperative behaviour in structured populations. To address this issue, we propose two new dispersal modes, parent-preferred and offspring-preferred dispersal, incorporate them into the birth–death update rule, and consider the resultant strategy evolution in the prisoner's dilemma on random-regular, small-world, and scale-free networks, respectively. We find that parent-preferred dispersal favours the evolution of cooperation in these different types of population structures, while offspring-preferred dispersal inhibits the evolution of cooperation in homogeneous populations. On scale-free networks when the strength of parent-preferred dispersal is weak, cooperation can be enhanced at intermediate strengths of offspring-preferred dispersal, and cooperators can coexist with defectors at high strengths of offspring-preferred dispersal. Moreover, our theoretical analysis based on the pair-approximation method corroborates the evolutionary outcomes on random-regular networks. We also incorporate the two new dispersal modes into three other update rules (death-birth, imitation, and pairwise comparison updating), and find that similar results about the effects of parent-preferred and offspring-preferred dispersal can again be observed in the aforementioned different types of population structures. Our work, thus, unveils robust effects of preferential dispersal modes on the evolution of cooperation in different interactive environments.

Inter-parent distance affects reproductive success in two clonal dwarf shrubs, Vaccinium myrtillus and Vaccinium vitis-idaea (Ericaceae)

2002 ◽  
Vol 80 (8) ◽  
pp. 875-884 ◽  
Author(s):  
Carolin Nuortila ◽  
Juha Tuomi ◽  
Kari Laine
Keyword(s):  
Reproductive Success ◽  
Natural Populations ◽  
Vaccinium Myrtillus ◽  
Seed Number ◽  
Genetic Population ◽  
Pollen Donor ◽  
Hand Pollination ◽  
Population Structures ◽  
Limited Dispersal ◽  
Vaccinium Myrtillus L

Clonal propagation and limited dispersal of seeds lead to genetic population structures in which most potential mates are relatives. If the species suffers from inbreeding depression or is self-incompatible, the number of seeds matured per fruit may be limited by the lack of outcrossing by unrelated pollen. We tested for distance-related genetic structure by hand-pollinating plants at increasing distances and measuring fruit set (berries/pollinated flowers) and seed number per fruit in natural populations of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.). Bagging of the flower buds without natural (pollination by insects) or hand-pollination yielded almost no fruit or seed, suggesting that the species are obligately insect pollinated. Self-pollination led to a significant reduction in seed number per fruit and increased seed abortion compared with cross-pollination. Moreover, seed number increased with increasing distance between the pollen donor and pollen recipient. Flight distances of bumblebees were estimated for bilberry by monitoring between-flower and, for lingonberry, between-inflorescence flight distances. About 90% of all flights were at distances of less than 1 m. At this distance, we observed less than the maximum seed number per fruit in hand-pollinations in both study species. Consequently, clonal growth is likely to be an important factor that constrains fruit and seed number in these species.Key words: bumblebee forage distance, clonal, hand-pollination, inter-parent distance, reproductive success, Vaccinium.

scholarly journals Ordering structured populations in multiplayer cooperation games

2016 ◽  
Vol 13 (114) ◽  
pp. 20150881 ◽  
Author(s):  
Jorge Peña ◽  
Bin Wu ◽  
Arne Traulsen
Keyword(s):  
Population Structure ◽  
Spatial Structure ◽  
Structured Populations ◽  
Evolution Of Cooperation ◽  
Multiplayer Games ◽  
Spatial Games ◽  
Population Structures ◽  
Single Structure ◽  
Containment Order ◽  
Update Rules

Spatial structure greatly affects the evolution of cooperation. While in two-player games the condition for cooperation to evolve depends on a single structure coefficient, in multiplayer games the condition might depend on several structure coefficients, making it difficult to compare different population structures. We propose a solution to this issue by introducing two simple ways of ordering population structures: the containment order and the volume order. If population structure is greater than population structure in the containment or the volume order, then can be considered a stronger promoter of cooperation. We provide conditions for establishing the containment order, give general results on the volume order, and illustrate our theory by comparing different models of spatial games and associated update rules. Our results hold for a large class of population structures and can be easily applied to specific cases once the structure coefficients have been calculated or estimated.

Allee effects drive the coevolution of cooperation and group size in high reproductive skew groups

2020 ◽  
Vol 31 (3) ◽  
pp. 661-671
Author(s):  
Brian A Lerch ◽  
Karen C Abbott
Keyword(s):  
Group Size ◽  
Social Evolution ◽  
Reproductive Skew ◽  
Evolution Of Cooperation ◽  
Positive Density ◽  
Allee Effects ◽  
Group Level ◽  
African Wild Dogs ◽  
Population Structures ◽  
Wild Dogs

Abstract The evolution of cooperation between conspecifics is a fundamental evolutionary puzzle, with much work focusing on the evolution of cooperative breeding. Surprisingly, although we expect cooperation to affect the population structures in which individuals interact, most studies fail to allow cooperation and population structure to coevolve. Here, we build two models containing group-level Allee effects (positive density dependence at low group sizes) to study the coevolution of cooperation and group size. Group-level Allee effects, although common in cooperatively breeding species, remain understudied for their evolutionary implications. We find that a trait that affects group size can cause increased cooperation to be favored evolutionarily even in a group with complete reproductive skew. In particular, we find a single evolutionarily stable attractor in our model corresponding to moderate helpfulness and group size. In general, our results demonstrate that, even in groups with complete reproductive skew, Allee effects can be important for the evolution of cooperation and that the evolution of cooperation may be closely linked to the evolution of group size. Further, our model matches empirical data in African wild dogs (Lycaon pictus), suggesting that it may have an application in understanding social evolution in this endangered species.

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