ANTHRO 7 Lecture Notes - Lecture 9: Simian, Orangutan, Reciprocal Altruism
Document Summary
If altruists preferentially interact with other altruists, altruism can evolve. Genetic kin are more similar to each other than are randomly chosen member of the same population-if individual a has a gene for altruism, a"s siblings are likely to have it too. A gene for altruism can be favored by selection if its bearers preferentially direct their altruism toward kin, because kin are likely to bear the same gene. Kin are likely to have copies of same genes. Proportions of genes shared by recent common descent (coefficient of relatedness), indicated as r (some examples) Full first cousins (i. e. ego"s parent full-sibling offspring): 0. 125. Where r is the coefficient of relatedness between altruist and recipient. B is the benefit of the action to the recipient. C is the cost of the action to the altruist. E. g. it would pay to refrain from producing one offspring if that would enable you full sibling to produce 3 additional offspring because (0. 5) (3)>1.
