February 17, 2014
When studying Ethology it is interesting to recognize how it links with evolution. When survival of the fittest dictates what behaviors will be kept within a population it raises some curious questions about why certain actions have survived. It would seem that an organisms behavior would be more predictable than it often is, however many creatures perform actions that seem inexplicable at first such as an altruistic act. When thinking about the benefits that certain behaviors may have it is useful to use game theory. Game theory allows predictions to be made of what the most rational behavior would be by assigning values to outcomes. It also allows an interaction between organisms to be understood better.
Game theory follows the assumption that organisms participating are rational and will therefore choose the action that shows the greatest benefit (Weibull 1997). Rationality however is not always the case as is shown in situations of punishment or vendettas (Fehl et al. 2012). By implementing game theory it is sometimes possible to recognize potential benefits to an activity that may seem irrational or as if it does not hold great benefit for those involved. Nash equilibrium would often be expected as it would give the greatest benefit for all participants however it does not always occur (Weibull 1997). Behaviour should generally reach equilibrium as behaviour that gives the highest reproductive success should be retained in a population. Though evolution does not always lead to equilibrium, game theory tends to favor cases in which it does (Hammerstein and Selten 1994).
When studying biology, game theory is useful in understanding behavior and can even potentially help understand why some organisms have the structures they have. For example when looking at an organism such as a deer which does not use their antlers to damage another deer when competing for a mate. By using game theory it can be more easily observed that while one member could gain increased fitness from this type of action, it would not be beneficial for the population and thus a middle ground is found where both members fight but one is not killed by the action (Hammerstein and Selten 1994).
When looking at game theory in the scope of evolution it can therefore not be assumed that an organism will be rational but rather that their behavior will lead to the greatest reproductive success (Hammerstein and Selten 1994). This can result in a behavior arising because it improves the fitness of close genetic relatives. Some members of a population may act in a way that may have a high cost for themselves but will improve fitness for other members related to them. In situations such as this, the relatives likely have the genetics that lead to this altruistic behavior and can pass it to future generations giving rise to behavior that is not entirely rational. Game theory is then useful in predicting what behavior will result in the greatest fitness for a population. By assigning values to greatest outcomes it is easier to understand why an animal behaves the way it does as well as how this action will benefit all that are participating in an interaction.
K. Fehl, R. D. Sommerfeld, D. Semmann, H-J. Krambeck, M. Milinski. 2012. I dare you to punish me – vendettas in games of cooperation. PLoS ONE 7: e45093.doi:10.1371/journal.pone.0045093
Hammerstein, P., & R. Selten. 1994. Game theory and evolutionary biology.Handbook of game theory with economic applications, 2, 929-993.
Weibull, J. W. 1997. Evolutionary game theory. MIT press.