Green-beard effect 3364638 181613686 2008-01-02T15:13:38Z Shoefly 142549 /* References */ The [[selfish gene theory]] postulates that [[natural selection]] will increase the frequency of those genes whose [[Phenotype|phenotypic]] effects ensure their successful [[DNA replication|replication]]. A [[gene]] for [[altruism]] can be favored by selection if the altruism is primarily directed at other individuals who share the same gene ([[kin selection]]). A '''green-beard effect''' gene (or linked genes) produces three phenotypic effects: #a perceptible [[Trait (biology)|trait]] &mdash; the hypothetical green beard; #recognition of this trait in others; and #preferential treatment to those recognized. So, this gene is directly recognizing copies of itself, regardless of average relatedness. Green-beard altruism could, strictly speaking, increase the presence of green-beard phenotypes in a population even if genes are assisting other genes that are not exact copies of themselves in a molecular sense: all that is required is that they produce the three phenotypic characteristics described above. Green beard genes are vulnerable to mutant genes arising that produce the perceptible trait without the helping behaviour. The idea of a green-beard gene was proposed by [[W. D. Hamilton|William D. Hamilton]] in his landmark article of 1964 and named by [[Richard Dawkins]] in his classic book ''[[The Selfish Gene]]'' of 1976. But only in 1998 was the first green-beard gene actually found in nature, most specifically in the [[Red imported fire ant]] (''Solenopsis invicta'').<ref name="RedImportedFireAnt">Keller & Ross. [http://www.nature.com/nature/journal/v394/n6693/abs/394573a0.html "Selfish genes: a green beard in the red fire ant"], ''Nature 394: 573-575'', August 6, 1998.</ref> ==References== <references/> * [[David Haig (biologist)|Haig, D.]] (1997) The social gene. In [[John Krebs|Krebs, J. R.]] & Davies, N. B. (editors) Behavioural Ecology: an Evolutionary Approach, 4th ed. pp. 284-304. Blackwell Publishers, London. * [[Richard Dawkins|Dawkins, R.]] (1976) ''[[The Selfish Gene]]''. Oxford University Press, Oxford. ISBN 0-19-217773-7 * Hamilton, W.D. (1964). The genetical evolution of social behaviour I and II. [[Journal of Theoretical Biology]], 7, 1-16 and 17-52. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=5875341&dopt=Abstract pubmed I] [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=5875340&dopt=Abstract pubmed II] * Queller, D. C., et al. (2003) Single-gene greenbeard effects in the social amoeba ''[[Dictyostelid|Dictyostelium]] discoideum''. [[Science (journal)]], 299, 105-106. [http://www.ruf.rice.edu/~evolve/pdf/20002001/Greenbeard.pdf Link] * [http://www.gnxp.com/MT2/archives/003367.html Green Beard Ethnic Nepotism?] on-line discussion about the topic by various authors, December 22, 2004, accessed Jan 2008 * Grafen, Alan [http://users.ox.ac.uk/~grafen/cv/grbeard.pdf Green beard as death warrant]] 1998, [[Nature (journal)]], accessed Jan 2008 - short discussion and critique on the possible existence of a green beard gene [[Category:Evolution]] [[Category:Evolutionary biology]] [[Category:Selection]] [[Category:Game theory]] [[pl:Efekt zielonej brody (biologia)]] [[fi:Vihreän parran ilmiö]]