Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

Veblen, Sen, and the formalization of evolutionary theory

It has been suggested that economics could benefit greatly from recent developments in evolutionary game theory. In fact, key authors in the study of the role of ethical norms in economic behavior like Amartya Sen argue that evolutionary game theory could contribute much to the study of social norms and behavior. Others have suggested that evolutionary game theory could be most helpful for formalizing the work of classic authors in evolutionary and institutional economics like Thorstein Veblen. Here I discuss the behavioral assumptions of evolutionary game theory models, and Jorgen Weibull's approach in particular. I will argue that Weibull's models, and evolutionary game theory in general, pose overly strong restrictions on the explanation of human behavior, which limit the potential of evolutionary explanation. I also suggest Tony Lawson's population-variety-reproduction-selection (PVRS) model as an alternative evolutionary framework that can successfully accommodate developments in behavioral economics, while also providing a solution to important critiques of Darwinian evolutionary analysis made by Richard Nelson, among others.info:eu-repo/semantics/publishedVersio

Evolutionary processes in replicating DNA species

Eine wichtige Triebfeder der Darwinschen Evolution verschiedener Spezies sind deren gegenseitige Wechselwirkungen innerhalb eines Ökosystems. Das Studium dieser Ökosysteme erlaubt es daher, deren zugrunde liegende evolutionäre Mechanismen zu verstehen. Dies wird allerdings oft durch ihre Komplexität oder die lange Lebensdauer mancher Spezies erschwert. Modellsysteme können dabei helfen diese Probleme zu überwinden indem sie die Kontrolle entscheidender Parameter wie etwa der Konzentration von Ressourcen oder Degradationsraten erlauben. In dieser Arbeit werden DNA-Moleküle die sich mit Hilfe von Enzymen replizieren als Modellsystem genutzt um zwei evolutionäre Phänomene zu beleuchten: Kooperation in der frühen Evolution und zyklische Inhibierung verschiedener Spezies. Im ersten Teil dieser Arbeit wird die Kooperation zwischen DNA-Spezies untersucht. Dazu wurden zwei Spezies benutzt die eine Hairpin-Sekundärstruktur bildeten, weshalb sie in einer Polymerase-Kettenreaktion nur langsam replizierten. Eine Selektion von schnelleren Replikatoren durch Verdünnungen führte zum Aussterben dieser Hairpins. Hatten sie allerdings die gleiche Loop-Sequenz, kooperierten sie und erzeugten eine Kreuzung welche keine Sekundärstruktur aufwies und daher die Verdünnungen überlebte. Das Umkehren der Reaktion erlaubte es die Hairpins wieder zu erzeugen und zeigte, dass deren Information erhalten blieb. Die Experimente demonstrierten wie Fitness und Komplexität in einem Oligonukleotidpool durch eine Kreuzung gesteigert werden können. Der zweite Abschnitt beschäftigt sich mit der zyklischen Inhibierung von Spezies in einem Schere-Stein-Papier Spiel. Dabei verfolgen drei Spezies eine vererbbare Strategie, welche zur Inhibierung einer anderen Spezies führt: Papier wickelt Stein ein, Stein schleift Schere und Schere zerschneidet Papier. Eine Möglichkeit dies auf molekularer Ebene umzusetzen ist die DNA-Toolbox, welche es erlaubt biochemische Reaktionsnetzwerke zu erstellen, in denen die Spezies DNA-Moleküle sind welche sich mithilfe von Enzymen replizieren. Zweidimensionale Simulationen mit einem Reaktions-Diffusions-Modell der DNA-Toolbox zeigten phasenverschobene Oszillationen und Spiralwellen. Durch räumliche Heterogenitäten konnten die dynamischen Muster beeinflusst werden. Für die experimentelle Umsetzung wurde ein Sequenz-Screening durchgeführt, dessen vorläufige Ergebnisse hier präsentiert werden. Die Erstellung des vollen Systems würde es ermöglichen die Bedingungen für die zeitlichen und räumlichen Oszillationen experimentell zu bestimmen und deren Robustheit gegenüber Störungen zu testen. Die DNA-Toolbox erlaubt es auch andere biologische Prozesse zu untersuchen, wie etwa die Regulierung genetischer Netzwerke. Im dritten Abschnitt wurde sie genutzt um einen experimentell erzeugten Morphogen-Gradienten zu interpretieren. Dazu reagierte eine autokatalytische DNA-Spezies mit dem Morphogen-Gradienten in einem Reaktions-Diffusions-Prozess. Es bildete sich eine Wellenfront, welche durch den Gradienten verlangsamt und lokalisiert wurde. Messungen der Position, Geschwindigkeit und Breite der Wellenfront wurden durchgeführt. Ähnliche Prozesse sind in der Embryogenese von Lebewesen zu finden, bei der der Morphogen-Gradient an genetische Netzwerke gekoppelt ist. Zusammengefasst zeigt sich, dass DNA und Enzyme nützliche Modellsysteme sind um komplexe biologische Phänomene zu untersuchen. Der bottom-up Ansatz erlaubt es unterschiedliche Aspekte wie Kooperation oder Embryogenese mit ähnlichen Techniken zu erforschen.The interaction of species in ecosystems is one of the main driving forces of Darwinian evolution. Observing the development of ecosystems allows to draw conclusions about the underlying evolutionary mechanisms. However, such observations are typically difficult, because of the complexity of ecosystems and the long lifetime of some species. Simple model systems that allow the precise control of key parameters, e.g. resource concentrations and degradation rates, can overcome this problems. Here, DNA molecules that replicate with the help of an enzymatic machinery were chosen as model systems to look at evolution from two different perspectives: cooperation of species in the early earth and cyclical inhibition of species. In the first part of the thesis, cooperation between the DNA species was studied. Two different species were designed to have hairpin secondary structures that slowed down replication during a polymerase chain reaction. Selection for fast replicators by serial dilutions resulted in an extinction of the hairpin species. However, when the two hairpin species only differed in their stems, but had the same loop sequence, they cooperated and formed crossbreeds. The crossbreeds lacked the secondary structure and survived the dilutions. Reversing the reaction resulted in reemergence of the hairpin species, demonstrating that the information was preserved. The presented results show how fitness and complexity of oligonucleotide pools on the early earth could have been increased by a simple crossbreeding step. In the second part, cyclical inhibition of species in a rock-paper-scissors game was studied. In such a game, three species play an inheritable strategy, where each species inhibits another species: paper wraps rock, rock crushes scissors, and scissors cut paper. One possibility to implement such a game on the molecular level is the DNA-toolbox: a framework to build biochemical reaction-networks where short DNA molecules are replicated by a polymerase and a nickase. Two-dimensional simulations with a reaction-diffusion model of the DNA-toolbox resulted in phase-shifted oscillations in time and characteristic chiral waves. Addition of spatial heterogenities to the simulations allowed to modify the the dynamic patterns and even could arrest them. For an experimental realization, a sequence screen to find suitable DNA species was performed and preliminary results are presented. Accomplishing the formation of the full system offers the opportunity to experimentally test the conditions needed for spatio-temporal oscillations and to probe their robustness to perturbations. The established DNA-toolbox can be used to study other complex biological processes, e.g. regulation of genetic networks. In the third part of the thesis, the DNA-toolbox is applied to interpret an experimentally created morphogen gradient. A self-replicating species reacts with a morphogen gradient in a reaction-diffusion process. This resulted in the formation of a traveling wavefront that localized in the gradient. Measurements of the positions, velocities and widths of the wavefronts are presented and analyzed. In biology, similar processes are found in embryogenesis, where a morphogen gradient is coupled to a genetic network. Taken together, model systems built of DNA and enzymes are useful tools to study complex biological phenomena. The bottom-up approach allows to tackle diverse topics like cooperation or embryogenesis with similar techniques

Economic description of tolerance in a society with asymmetric social cost functions

The evolutionary game dynamics of social tolerance among heterogeneous economic agents have been discussed in an economic interaction model with asymmetric social cost functions, where the individual cost depends only on the share of intolerant people in the opposite group. We show that, very different from the symmetric function case studied previously, economic interactions between individuals in a society with asymmetric social cost functions can be exactly solved in phase plane, and rich behaviours can be revealed by using algebraic approach. Our contribution consists in offering the explicit formula of evolutionary trajectories in the phase plane for the first time. The property of equilibrium is shown to be closely related to the group populations. Based on the explicit formula in the phase plane, the equilibriums of the evolutionary dynamics can be easily identified, and the evolutionary trajectory can be exactly analysed. We also show that the explicit solutions obtained would be especially suited to effective control of the evolutionary dynamics of social tolerance. The necessary and sufficient conditions of the full tolerance equilibrium under asymmetric social cost function are also discussed, which provides guidance and reference to set policies and development strategy of social tolerance

Evolution of trust in structured populations

The trust game, derived from a notable economics experiment, has recently attracted interest in the field of evolutionary dynamics. In a prevalent version of the evolutionary trust game, players adopt one of three strategies: investor, trustworthy trustee, or untrustworthy trustee. Trustworthy trustees enhance and share the investment with the investor, whereas untrustworthy trustees retain the full amount, betraying the investor. Following this setup, we propose a two-player version of the trust game, which is analytically feasible. Based on weak selection and pair approximation, we explore the evolution of trust in structured populations, factoring in four strategy updating rules: pairwise comparison (PC), birth-death (BD), imitation (IM), and death-birth (DB). Comparing structured populations with well-mixed populations, we arrive at two main conclusions. First, in the absence of untrustworthy trustees, there is a saddle point between investors and trustworthy trustees, with collaboration thriving best in well-mixed populations. The collaboration diminishes sequentially from DB to IM to PC/BD updating rules in structured populations. Second, an invasion of untrustworthy trustees makes this saddle point unstable and leads to the extinction of investors. The 3-strategy system stabilizes at an equilibrium line where the trustworthy and untrustworthy trustees coexist. The stability span of trustworthy trustees is maximally extended under the PC and BD updating rules in structured populations, while it decreases in a sequence from IM to DB updating rules, with the well-mixed population being the least favorable. This research adds an analytical lens to understanding the evolution of trust in structured populations.Comment: 15 pages, 5 figure

Tough Behavior in the Repeated Bargaining Game. A Computer Simulation Study.

Bargaining behavior occupies an important part in economics literature, or social sciences in general. Although there is an extensive simulation literature on social tradeoff in the Prisoner's Dilemma and the one-shot bargaining game, little has been done for the repeated bargaining game. Part of reason for this neglect is that, despite having a continuum of Nash equilibria, under homogeneous settings, the one shot bargaining game consistently gives a stable equilibrium of fairness (50-50 division), robust to many kind of tough perturbations. However, it's true that social interaction doesn't always yield unconditional egalitarianism. Hence we simulate a population of homogeneous agents playing the repeated bargaining game to test the stability of the 50-50 norm under evolutionary force. It turns out that when it comes to repeated interaction, the fair norm no longer stands strong

Evolutionary processes in replicating DNA species

Eine wichtige Triebfeder der Darwinschen Evolution verschiedener Spezies sind deren gegenseitige Wechselwirkungen innerhalb eines Ökosystems. Das Studium dieser Ökosysteme erlaubt es daher, deren zugrunde liegende evolutionäre Mechanismen zu verstehen. Dies wird allerdings oft durch ihre Komplexität oder die lange Lebensdauer mancher Spezies erschwert. Modellsysteme können dabei helfen diese Probleme zu überwinden indem sie die Kontrolle entscheidender Parameter wie etwa der Konzentration von Ressourcen oder Degradationsraten erlauben. In dieser Arbeit werden DNA-Moleküle die sich mit Hilfe von Enzymen replizieren als Modellsystem genutzt um zwei evolutionäre Phänomene zu beleuchten: Kooperation in der frühen Evolution und zyklische Inhibierung verschiedener Spezies. Im ersten Teil dieser Arbeit wird die Kooperation zwischen DNA-Spezies untersucht. Dazu wurden zwei Spezies benutzt die eine Hairpin-Sekundärstruktur bildeten, weshalb sie in einer Polymerase-Kettenreaktion nur langsam replizierten. Eine Selektion von schnelleren Replikatoren durch Verdünnungen führte zum Aussterben dieser Hairpins. Hatten sie allerdings die gleiche Loop-Sequenz, kooperierten sie und erzeugten eine Kreuzung welche keine Sekundärstruktur aufwies und daher die Verdünnungen überlebte. Das Umkehren der Reaktion erlaubte es die Hairpins wieder zu erzeugen und zeigte, dass deren Information erhalten blieb. Die Experimente demonstrierten wie Fitness und Komplexität in einem Oligonukleotidpool durch eine Kreuzung gesteigert werden können. Der zweite Abschnitt beschäftigt sich mit der zyklischen Inhibierung von Spezies in einem Schere-Stein-Papier Spiel. Dabei verfolgen drei Spezies eine vererbbare Strategie, welche zur Inhibierung einer anderen Spezies führt: Papier wickelt Stein ein, Stein schleift Schere und Schere zerschneidet Papier. Eine Möglichkeit dies auf molekularer Ebene umzusetzen ist die DNA-Toolbox, welche es erlaubt biochemische Reaktionsnetzwerke zu erstellen, in denen die Spezies DNA-Moleküle sind welche sich mithilfe von Enzymen replizieren. Zweidimensionale Simulationen mit einem Reaktions-Diffusions-Modell der DNA-Toolbox zeigten phasenverschobene Oszillationen und Spiralwellen. Durch räumliche Heterogenitäten konnten die dynamischen Muster beeinflusst werden. Für die experimentelle Umsetzung wurde ein Sequenz-Screening durchgeführt, dessen vorläufige Ergebnisse hier präsentiert werden. Die Erstellung des vollen Systems würde es ermöglichen die Bedingungen für die zeitlichen und räumlichen Oszillationen experimentell zu bestimmen und deren Robustheit gegenüber Störungen zu testen. Die DNA-Toolbox erlaubt es auch andere biologische Prozesse zu untersuchen, wie etwa die Regulierung genetischer Netzwerke. Im dritten Abschnitt wurde sie genutzt um einen experimentell erzeugten Morphogen-Gradienten zu interpretieren. Dazu reagierte eine autokatalytische DNA-Spezies mit dem Morphogen-Gradienten in einem Reaktions-Diffusions-Prozess. Es bildete sich eine Wellenfront, welche durch den Gradienten verlangsamt und lokalisiert wurde. Messungen der Position, Geschwindigkeit und Breite der Wellenfront wurden durchgeführt. Ähnliche Prozesse sind in der Embryogenese von Lebewesen zu finden, bei der der Morphogen-Gradient an genetische Netzwerke gekoppelt ist. Zusammengefasst zeigt sich, dass DNA und Enzyme nützliche Modellsysteme sind um komplexe biologische Phänomene zu untersuchen. Der bottom-up Ansatz erlaubt es unterschiedliche Aspekte wie Kooperation oder Embryogenese mit ähnlichen Techniken zu erforschen.The interaction of species in ecosystems is one of the main driving forces of Darwinian evolution. Observing the development of ecosystems allows to draw conclusions about the underlying evolutionary mechanisms. However, such observations are typically difficult, because of the complexity of ecosystems and the long lifetime of some species. Simple model systems that allow the precise control of key parameters, e.g. resource concentrations and degradation rates, can overcome this problems. Here, DNA molecules that replicate with the help of an enzymatic machinery were chosen as model systems to look at evolution from two different perspectives: cooperation of species in the early earth and cyclical inhibition of species. In the first part of the thesis, cooperation between the DNA species was studied. Two different species were designed to have hairpin secondary structures that slowed down replication during a polymerase chain reaction. Selection for fast replicators by serial dilutions resulted in an extinction of the hairpin species. However, when the two hairpin species only differed in their stems, but had the same loop sequence, they cooperated and formed crossbreeds. The crossbreeds lacked the secondary structure and survived the dilutions. Reversing the reaction resulted in reemergence of the hairpin species, demonstrating that the information was preserved. The presented results show how fitness and complexity of oligonucleotide pools on the early earth could have been increased by a simple crossbreeding step. In the second part, cyclical inhibition of species in a rock-paper-scissors game was studied. In such a game, three species play an inheritable strategy, where each species inhibits another species: paper wraps rock, rock crushes scissors, and scissors cut paper. One possibility to implement such a game on the molecular level is the DNA-toolbox: a framework to build biochemical reaction-networks where short DNA molecules are replicated by a polymerase and a nickase. Two-dimensional simulations with a reaction-diffusion model of the DNA-toolbox resulted in phase-shifted oscillations in time and characteristic chiral waves. Addition of spatial heterogenities to the simulations allowed to modify the the dynamic patterns and even could arrest them. For an experimental realization, a sequence screen to find suitable DNA species was performed and preliminary results are presented. Accomplishing the formation of the full system offers the opportunity to experimentally test the conditions needed for spatio-temporal oscillations and to probe their robustness to perturbations. The established DNA-toolbox can be used to study other complex biological processes, e.g. regulation of genetic networks. In the third part of the thesis, the DNA-toolbox is applied to interpret an experimentally created morphogen gradient. A self-replicating species reacts with a morphogen gradient in a reaction-diffusion process. This resulted in the formation of a traveling wavefront that localized in the gradient. Measurements of the positions, velocities and widths of the wavefronts are presented and analyzed. In biology, similar processes are found in embryogenesis, where a morphogen gradient is coupled to a genetic network. Taken together, model systems built of DNA and enzymes are useful tools to study complex biological phenomena. The bottom-up approach allows to tackle diverse topics like cooperation or embryogenesis with similar techniques