演化博弈论(清华大学)

进化博弈 Evolutionary Games
第13章 Chapter 13
进化博弈 Evolutionary Games
目前为止我们学过了具有多种不同特征的博弈： We have so far studied games with many different features:
同时和序贯博弈 Simultaneous and sequential moves 零和与非零和博弈 Zero-sum and non-zero-sum payoffs 操纵未来博弈规则的策略性行动 Strategic moves to manipulate rules of games to come 一次性和重复博弈 One-shot and repeated play 许多人同时进行的集体博弈 Games of collective action in which a large number of people play simultaneously
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进化博弈 Evolutionary Games
所有这些博弈中的参与者都是理性的：每个参 与者…… All the players in all these games are rational: each player……
……具有内在一致的价值体系 has an internally consistent value system ……能够计算其策略选择的后果 can calculate the consequences of her strategic choices ……作出最符合其利益的选择 makes choice that best favors her interests
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进化博弈 Evolutionary Games
对理性可能的替代方法可以从生物学的进化和进化动 力学中找到，在那里…… One possible alternative to rationality can be found in the biological theory of evolution and evolutionary dynamics, where……
……好的策略可以得到更多的奖励 good strategies will be rewarded with higher payoffs ……参与者可以观察或模仿成功者并试验新的策略 players can observe or imitate success and experiment with new strategies ……随着参与者在参加博弈中获得经验，好的策略将会得到 更经常的使用，坏的策略得到更少的使用。 good strategies will be used more often and bad strategies less often, as players gain experience playing the game.
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内容提要 Outline
*框架 The framework （*重点或难点） *囚徒困境 Prisoners’ dilemma 小鸡 Chicken 保证博弈 The assurance game *不同物种间作用 Interactions across species 鹰鸽博弈 The hawk-dove game *种群中有三种表现型 Three Phenotypes in the Population 一般理论 Some General Theory 群体博弈（略） Playing the field 合作与利他的进化
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框架 The Framework
生物学中的进化过程提供了社会科学家使用的 博弈论的平行物。 The process of evolution in biology offers a parallel to the theory of games used by social scientists. 这一理论建立在三个基本原则上： This theory rests on three fundamentals:
异质性 Heterogeneity 适应性 Fitness 选择 Selection
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框架 The Framework
动物行为的相当一部分是由物种决定的；一个或多个 基因的联合体（基因型）支配着某一特定的行为模式 （称为行为表现型）。 A significant part of animal behavior is generically determined; a complex of one or more genes (genotype) governs a particular pattern of behavior, called a behavior phenotype. 例子 Examples
鸟翅膀的空气动力学特征 Aerodynamic characteristics of a bird’s wings 好斗或者合作的行为 Aggressive or cooperative behavior 筑巢的位置 Locations of nesting sites
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框架 The Framework
自然界基因库的多样性保证了种群当中表现型 的异质性。 Natural diversity of the gene pool ensures a heterogeneity of phenotypes in the population. 某些行为比其他行为更适合于当前环境，一种 表现型的成功可以用适应性来定量测量。 Some behaviors are better suited than others to the prevailing conditions, and the success of a phenotype is given a quantitative measure called its fitness.
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