Altruism through beard chromodynamics

Vincent A.A. Jansen (1) , Minus van Baalen (2)

1 RHUL - Royal Holloway [University of London]
2 Laboratoire Ecologie et évolution

The evolution of altruism, a behaviour that benefits others at one's own fitness expense, poses a darwinian paradox. The paradox is resolved if many interactions are with related individuals so that the benefits of altruism are reaped by copies of the altruistic gene 12 , a mechanism called kin selection. However, in other individuals recognition of altruists could provide an alternative route towards 1,3–5 . Arguably the simplest recognition the evolution of altruism 1,3 . system is a conspicuous, heritable tag, such as a green beard 6–8 , the ‘green Despite the fact that such genes have been reported 3 has often been dismissed because it is unlikely that a beard effect' 1,3,9 . Here single gene can code for altruism and a recognizable tag we model the green beard effect and find that if recognition and altruism are always inherited together, the dynamics are highly unstable, leading to the loss of altruism. In contrast, if the effect is caused by loosely coupled separate genes, altruism is facilitated through beard chromodynamics in which many beard colours co- occur. This allows altruism to persist even in weakly structured populations and implies that the green beard effect, in the form of a fluid association of altruistic traits with a recognition tag, can be much more prevalent than hitherto assumed.

Mots clés: evolution; altruism; kin selection; communication; green beards

Domaines: Ecologie, Environnement

Vincent A.A. Jansen, Minus van Baalen. Altruism through beard chromodynamics. Nature, 2006, 440, pp.663--666. ⟨hal-00557996⟩