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Cheating is evolutionarily assimilated with cooperation in the continuous snowdrift game.

Sasaki T, Okada I - BioSystems (2015)

Bottom Line: Recent theoretical evidence on the snowdrift game suggests that gradual evolution for individuals choosing to contribute in continuous degrees can result in the social diversification to a 100% contribution and 0% contribution through so-called evolutionary branching.Subsequently, conditions are clarified under which gradual evolution can lead a population consisting of those with 100% contribution and those with 0% contribution to merge into one species with an intermediate contribution level.Importantly, this implies that allowing the gradual evolution of cooperative behavior can facilitate social inequity aversion in joint ventures that otherwise could cause conflicts that are based on commonly accepted notions of fairness.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Mathematics, University of Vienna, 1090 Vienna, Austria; Evolution and Ecology Program, International Institute for Applied Systems Analysis (IIASA), 2361 Laxenburg, Austria. Electronic address: tatsuya.sasaki@univie.ac.at.

No MeSH data available.


Related in: MedlinePlus

Sign plots of differences in the average cooperation level and payoff over the populations with a classical mixed equilibrium with  in Eq. (18) and the interior singular strategy with  in Eq. (13). Parameters are as in Fig. 2. For each index, the sign is “+”, if the value in the singular-strategy case is greater than that in the mixed-equilibrium case; otherwise, “−”.
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fig0025: Sign plots of differences in the average cooperation level and payoff over the populations with a classical mixed equilibrium with in Eq. (18) and the interior singular strategy with in Eq. (13). Parameters are as in Fig. 2. For each index, the sign is “+”, if the value in the singular-strategy case is greater than that in the mixed-equilibrium case; otherwise, “−”.

Mentions: First, we rewrite the difference in the cooperation levels at equilibria in Eqs. (13) and (18), as follows:(21)xˆ−nˆ=(b2−c2)(2b2+b1−c2−c1)2b2(2b2−c2).Then, the average payoff for the monomorphic population with an interior singular strategy is given by(22)P¯(xˆ)=(b1−c1)(−4b1b2+3b1c2−c1c2)4(2b2−c2)2.It should be stressed that maximal average payoffs in dimorphic populations, as well as in monomorphic populations, cannot be expected to predict the evolutionary outcome. In the discrete snowdrift game, at its interior mixed equilibrium in Eq. (5), the average payoff over the population is given by(23)P¯(nˆ)=(b2+b1)(−b2−b1+c2+c1)2b2.Indeed, our numerical investigations indicated that in specific parameters, the adaptive dynamics favor the second best equilibria, which bring about a lower level of average cooperation and/or payoff over the population (Fig. 5).


Cheating is evolutionarily assimilated with cooperation in the continuous snowdrift game.

Sasaki T, Okada I - BioSystems (2015)

Sign plots of differences in the average cooperation level and payoff over the populations with a classical mixed equilibrium with  in Eq. (18) and the interior singular strategy with  in Eq. (13). Parameters are as in Fig. 2. For each index, the sign is “+”, if the value in the singular-strategy case is greater than that in the mixed-equilibrium case; otherwise, “−”.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4441111&req=5

fig0025: Sign plots of differences in the average cooperation level and payoff over the populations with a classical mixed equilibrium with in Eq. (18) and the interior singular strategy with in Eq. (13). Parameters are as in Fig. 2. For each index, the sign is “+”, if the value in the singular-strategy case is greater than that in the mixed-equilibrium case; otherwise, “−”.
Mentions: First, we rewrite the difference in the cooperation levels at equilibria in Eqs. (13) and (18), as follows:(21)xˆ−nˆ=(b2−c2)(2b2+b1−c2−c1)2b2(2b2−c2).Then, the average payoff for the monomorphic population with an interior singular strategy is given by(22)P¯(xˆ)=(b1−c1)(−4b1b2+3b1c2−c1c2)4(2b2−c2)2.It should be stressed that maximal average payoffs in dimorphic populations, as well as in monomorphic populations, cannot be expected to predict the evolutionary outcome. In the discrete snowdrift game, at its interior mixed equilibrium in Eq. (5), the average payoff over the population is given by(23)P¯(nˆ)=(b2+b1)(−b2−b1+c2+c1)2b2.Indeed, our numerical investigations indicated that in specific parameters, the adaptive dynamics favor the second best equilibria, which bring about a lower level of average cooperation and/or payoff over the population (Fig. 5).

Bottom Line: Recent theoretical evidence on the snowdrift game suggests that gradual evolution for individuals choosing to contribute in continuous degrees can result in the social diversification to a 100% contribution and 0% contribution through so-called evolutionary branching.Subsequently, conditions are clarified under which gradual evolution can lead a population consisting of those with 100% contribution and those with 0% contribution to merge into one species with an intermediate contribution level.Importantly, this implies that allowing the gradual evolution of cooperative behavior can facilitate social inequity aversion in joint ventures that otherwise could cause conflicts that are based on commonly accepted notions of fairness.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Mathematics, University of Vienna, 1090 Vienna, Austria; Evolution and Ecology Program, International Institute for Applied Systems Analysis (IIASA), 2361 Laxenburg, Austria. Electronic address: tatsuya.sasaki@univie.ac.at.

No MeSH data available.


Related in: MedlinePlus