Wd Hamilton Quotes

Hamilton's original contribution was to realize that indirect fitness effects impact upon the purpose of adaptation. The basic condition for natural selection to favor any trait is that the individuals who carry genes for this trait are, on average, fitter than those who do not. However, the adaptations that subsequently evolve are not designed for maximizing the individual's personal fitness, but rather her inclusive fitness, i.e., the sum of all the fitness effects that she has on all of her genetic relatives, each increment or decrement being weighted by the corresponding coefficient of genetic relatedness (Hamilton 1964). In other words, the adaptive agent remains the same as in the traditional Darwinian view (i.e., the individual organism), but the adaptive agenda is changed. This idea has subsequently been formalized by Grafen (2006), who has shown the mathematical connection between the dynamics of natural selection and an optimization program in whih the individual strives to maximize her inclusive fitness, for a wide class of models, including those that allow for social interaction between relatives. Grafen A. 2006. Optimization of inclusive fitness. J Theor Biol 238: 541-563. Hamilton WD. 1964. The genetical evolution of social behaviour I & II. J Theor Biol 7: 1-52.

.... by our lofty standards animals are poor liars.

So how can genetics explain altruistic scenarios? In 1964, WD Hamilton proposed a ‘model of inclusive fitness’ which suggested “no one is prepared to sacrifice his life for any single person but that everyone will sacrifice it when he can thereby save more than two brothers, or four half-brothers, or eight first cousins …” Conversely, while selfish behaviour against immediate siblings or close relatives will not evolve, from a gene’s point of view, “it is worthwhile to deprive a large number of distant relatives in order to extract a small reproductive advantage.”54