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The Game of Evolution

While we have only scratched the surface of the myriad applications of game theory in class, it is easily seen that the the study and utility of game theory traverses multiple disciplines of study. Beyond the application of game theory for the study of human behavior, game theory can also be a powerful tool in the analysis of animal behavior. Charles Darwin’s Origin of The Species defined evolution as the marked change in animal traits or phenotypes over sucessive generations – a consequence of natural selection and gene propagation. The forces and mechanisms that drive natural selection and evolution create the “games” in which individuals within a population must inevitably play. These “games” exist within all animal ecosystems, influencing both inter-species and intra-species behavior.

“Games” are an integral part of all animal behaviors. The “games” found in nature involves the interactions between individuals vying for a share of limited resources. Acquired resources, such as food, territory, and/or reproductive mates constitute the payoff or reward for a particular strategy – a higher payoff confers higher evolutionary fitness. With each strategy, however, there are inherent costs or risks involved. Namely, obtaining resources exhausts physical energy that may be better expended elsewhere, or it may involve potentially dangerous aggressive behaviors. To ensure evolutionary fitness – that is, reproductive success and propogation of one’s genes – an animal must weigh the risks and benefits of any particular behavior. While using game theory to analyze and predict animal behavior seems simple enough, game theory provides a useful approach in understanding more complex animal behaviors.

A long misunderstood behavior in evolutionary biology, altruism is a behavior that, at first glance, seems to confer no evolutionary advantage or individual payoff. Among animals, these behaviors may include resource sharing, sibling offspring rearing, and inter-population alarm calls –  all behaviors that seem to sacrifice the fitness of the altruistic individual. The scientific literature linked below describes a sort of game theory approach toward the analysis of altruistic behaviors in animal populations. If the theory of evolution is to be accepted, altruistic behaviors that have an inherent cost in fitness therefore, cannot evolve. However, utilizing a “gene” centered perspective, biologists can conceptualize the existence of altruism within an evolutionary framework.  Within animal populations, individuals with the genotype (genetic trait) for altruistic behavior increase “in frequency if those with the genotype on average get more benefit from the behavior of others than they pay in cost for their own behavior.” In other words, if a genetic trait for altruistic behavior confers a net benefit to all of the individuals in a population with the same gene, the frequency of the gene will increase via natural selection and gene propagation. In considering the indirect payoffs of altruism, evolutionary biologists can thus modify the parameters of the evolutionary “game” to include indirect payoffs. To model payoffs within animal populations, biologists use Hamilton’s rule, rB > C to predict whether or not a particular behavior will occur in a population. The variable r measures genetic relatedness between two individuals (taking into account evolutionary benefit at the gene level) in a population , B measures the net benefit acquired from such behavior, and C measures the cost of the behavior of interests. Thus, if the relatedness between individuals decrease and/or the net benefit of altruism exceeds the cost of such behavior, natural selection will select against altruism.

Using Hamilton’s model and game theory as a basis to study behavior, behavioral biologists can thus develop more comprehensive systems or “games” to predict animal behaviors within a population. Such models can be applied to many animal populations including bee colonies, naked mole rats colonies, and even ant colonies. While behaviors in animal populations are too complex to form a perfect working model, the addition of the variables r and B to the evolutionary “game” creates a more suitable model to predict behavior in animal populations. Evolutionary biologist, Richard Dawkins was the first to coin the term the “selfish gene” due to the self perpetuating nature of successful genes. This consideration is yet another variable that dictates the rules of all animal “games.” Thus, studying behavior at the “gene” level adds another dimension in the evolutionary “game” that must be considered if we hope to understand the mechanisms behind animal, including human, behavior.

http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2006.01146.x/abstract

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2 Responses to “ The Game of Evolution ”

  • weiwei kite

    Thus, studying behavior at the “gene” level adds another dimension in the evolutionary “game” that must be considered if we hope to understand the mechanisms behind animal, including human, behavior.iphone 5 cases

  • wii remote controller

    The Game of Evolution

    While we have only scratched the surface of the myriad applications of game theory in class, it is easily seen that the the study and utility of game theory traverses multiple disciplines of study. Beyond the application of game theory for the study of human behavior

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