Versions of the FormulaEdit
r: relatedness. The proportion of alleles shared between the altruist and the recipient. (Parents share roughly 50% of an organism's alleles, siblings share roughly 50% of an organism's alleles, first cousins share roughly 12.5% of an organism's alleles.)
B: Benefit to the recipient. The additional number of offspring produced by the recipient as a result of the altruist's behavior.
C: Cost to the altruist. The number of offspring the altruist was unable to produce as a result of the altruistic behavior.
r B > C or r B - C >0
Hardwick, S. (2012). Hamilton’s Rule and the Evolution of Altruism. Retrieved from http://www.youtube.com/watch?v=unUG0BPMaIw .
Gardner, A., West, S.A. & Wild, G. (2011) The genetical theory of kin selection. Journal of Evolutionary Biology, 1020-1043.