Selfish genes: A green beard in the red fire ant

Abstract

A 'green-beard' gene is defined as a gene that causes a phenotypic effect (such as the presence of a green beard or any other conspicuous feature), allows the bearer of this feature to recognize it in other individuals, and causes the bearer to behave differently towards other individuals depending on whether or not they possess the feature. Such genes have been proposed on theoretical grounds to be agents mediating both altruism and intragenomic conflicts, but until now few, if any, of these genes have been identified.