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Altruism and Evolutionary Game Theory


Game Theory could be applied to biology, especially in the context of biological altruism and family. A famous example is that of monkeys who howl to alert other monkeys when they see predators. In doing so, they alert predators to their position thus putting them at extremely great risk. If they would not howl, they would be able to quietly escape while fellow monkeys get eaten. However, monkeys have grown to evolve this howling trait as it is ultimately beneficial in the long-run.

This is mainly due to the passing of genes through non-direct descendants. If a monkey has children, those children have 50% of that monkey’s DNA as they are one edge apart. A niece or nephew monkey will have 25% of that monkey’s DNA as those monkeys are two edges apart (monkey -à sibling, sibling à niece/nephew). Essentially, the amount of DNA monkeys share is equal to (50%* number of edges). Thus, it is in the monkey’s interest to call out and warn its sibling if it thinks more of its own DNA will be passed down in calling than not calling. Thus, the lives of potentially three nephew monkeys are worth more to a father monkey than that father monkey’s own son as 3 * 25% >  1 * 50%.

Thus, traits for altruism are passed down by these monkeys as calling out is ultimately individually beneficial. Should a monkey not call out, it may be able to have children of its own, but it won’t pass down as much DNA as it would through the children of other monkeys. If this were not true, monkeys would not have evolved the trait to howl upon seeing predators. A selfish monkey is ultimately just hurting its own chances of passing down DNA. Consequentially, monkeys are much less likely to howl and perform other altruistic deeds for non-family members. There are obvious connections to social networks in the class, as the likeliness of altruism being performed is a consequence of edges and social clusters.


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