exists in many physical copies in the world, and which particular physical copy will be replicated and originate new copies does not matter from the gene's point of view. A selfish gene could be favored by selection by producing altruism among organisms containing it. The idea is summarized as follows: A gene in a somatic cell of an individual may forgo replication to promote the transmission of its copies in the germ line cells. It ensures the high value of p = 1 due to their constant contact and their common origin from the zygote. The kin selection theory predicts that a gene may promote the recognition of kinship by historical continuity: a mammalian mother learns to identify her own offspring in the act of giving birth; a male preferentially directs resources to the offspring of mothers with whom he has copulated; the other chicks in a nest are siblings; and so on. The expected altruism between kin is calibrated by the value of p, also known as the coefficient of relatedness. For instance, an individual has a p = 1/2 in relation to his brother, and p = 1/8 to his cousin, so we would expect, ceteris paribus, greater altruism among brothers than among cousins. In this vein, geneticist J. B. S. Haldane famously joked, "Would I lay down my life to save my brother? No, but I would to save two brothers or eight cousins." However, examining the human propensity for altruism, kin selection theory seems incapable of explaining cross-familiar, cross-racial and even cross-species acts of kindness, to which Richard Dawkins wrote: Green-beard effect Green-beard effects gained their name from a thought-experiment first presented by Bill Hamilton and then popularized and given its current name by Richard Dawkins who considered the possibility of a gene that caused its possessors to develop a green beard and to be nice to other green-bearded individuals. Since then, "green-beard effect" has come to refer to forms of genetic self-recognition in which a gene in one individual might direct benefits to other individuals that possess the gene.. Such genes would be especially selfish, benefiting themselves regardless of the fates of their vehicles. Since then, green-beard genes have been discovered in nature, such as Gp-9 in fire ants (Solenopsis invicta), csA in social amoeba (Dictyostelium discoideum), and FLO1 in budding yeast (Saccharomyces cerevisiae). Intragenomic conflict As genes are capable of producing individual altruism, they