Interactions between organisms can lie anywhere on a continuum between extreme conflict and extreme cooperation. Explaning this variation, and especially instances of cooperation, remains one of the greatest problems for evolutionary biology. We are addressing this with a mixture of experimental (bacteria), comparative (vertebrates) and theoretical techniques.

Recent and ongoing projects

• Social Evolution in Microbes
  
• Cooperation: kin selection
• Cooperation: between species (mutualisms)
• Spite & Punishment

Selected Relevant Publications
(click on paper titles to download a PDF)

Working Paper: West, S.A., El Mouden, C. & Gardner, A. Social evolution theory and its application to the evolution of cooperation in humans.

• Kümmerli, R., Gardner, A., West, S.A. & Griffin, A.S. (2009) Limited dispersal, budding dispersal, and cooperation: an experimental study. Evolution 63, 939-949.
• Rumbaugh, K.P., Diggle, S.P., Watters, C.M., Ross-Gillespie, A., Griffin, A.S. & West, S.A. (2009). Quorum sensing and the social evolution of bacterial virulence. Current Biology 19, 341-345.
• West, S.A., Griffin, A.S. & Gardner, A. (2008) Social semantics: how useful has group selection been? Journal of Evolutionary Biology 21, 374-385. This was a reply to DS Wilson's comment on our 2007 Social Semantics review. {Media} {Faculty of 1000}
• Diggle, S.P., Griffin, A.S., Campbell, G.S. & West. S.A. (2007) Cooperation and conflict in quorum-sensing bacterial populations. Nature 450, 411-414. {Media} {Making the paper} {Editorial} {Faculty of 1000}
  
• West, S.A., Griffin, A.S. & Gardner, A. (2007) Evolutionary explanations for cooperation. Current Biology, 17, R661-R672.
  
• Diggle, S.P., Gardner, A., West. S.A. & Griffin, A.S. (2007) Evolutionary theory of bacterial quorum sensing: when is a signal not a signal? Philosophical Transactions of The Royal Society.
• Gardner, A., West. S.A. & Barton, N.H. (2007) The relation between multilocus population genetics and social evolution theory. American Naturalist 169, 207-226.
• Gardner, A., West. S.A. & Griffin, A.S. (2007) Is bacterial persistence a social trait? PLOS One, 2(8), e752.
  
• Gardner, A., Hardy, I.C.W., Taylor, P.D. & West. S.A. (2007) Spiteful soldier production in polyembryonic parasitoid wasps. American Naturalist 169, 519-533.
  
• Lehmann, L., Keller, L., West, S.A. & Roze, D. (2007) Group selection and kin selection. Two concepts but one process. Proceedings of the National Academy of Science, USA, 104, 6736-6739.
  
• Ross-Gillespie, A., Gardner, A., West, S.A. & Griffin, A.S. (2007) Frequency dependence and cooperation: theory and a test with bacteria. American Naturalist, 170, 331-342.
  
• West, S.A., Griffin, A.S. & Gardner, A. (2007) Social semantics: altruism, cooperation, mutualism, strong reciprocity and group selection. Journal of Evolutionary Biology 20, 415-432.  {Faculty of 1000}
  
• West, S.A., Diggle, S.P., Buckling, A., Gardner, A. & Griffin, A.S. (2007) The social lives of microbes. Annual Review of Ecology, Evolution and Systematics, 38, 53-57.
  
• Gardner, A. & West, S.A. (2006) Demography, altruism, and the benefits of budding. Journal of Evolutionary Biology 19, 1707-1716.
• Gardner, A. & West. S.A. (2006) Spite. Current Biology 16, R662-R664.
• West, S.A., Gardner, A., & Griffin, A.S. (2006) Altruism. Current Biology 16, R482-R483.
• West, S.A., Griffin, A.S., Gardner, A. & Diggle, S.P. (2006) Social evolution theory for microbes. Nature Reviews Microbiology 4, 597-607.
• West, S.A., Gardner, A., Shuker, D.M., Reynolds, T., Burton-Chellow, M., Sykes, E.M., Guinee, M.A. & Griffin, A.S. (2006) Cooperation and the scale of competition in humans. Current Biology 16, 1103-1106. {Current Biology Commentary}  {Media}
• Innocent, T.M. & West, S.A. (2006) Social evolution: cooperation by conflict. Current Biology. 16, R365-R367.
• Griffin, A.S., Sheldon, B.C. & West, S.A. (2005) Cooperative breeders adjust offspring sex ratios to produce helpful helpers. American Naturalist 166, 628-632.
  
• Gardner, A. & West, S.A. (2004) Cooperation and punishment, especially in humans. American Naturalist, 164, 753-764.
• Gardner, A. & West, S.A. (2004) Spite among siblings. Science, 305, 1413-1414.
  
• Gardner, A. & West, S.A. (2004) Spite and the scale of competition. Journal of Evolutionary Biology 17, 1195-1203.  {Media}
• Gardner, A., West, S.A. & Buckling, A. (2004) Bacteriocins, spite and virulence. Proceedings of the Royal Society London Series B, 271, 1529-1535. {Science perspective}  {Media}
• Griffin, A.S., West, S.A. & Buckling, A. (2004) Cooperation and competition in pathogenic bacteria. Nature, 430, 1024-1027. {Nature News & Views} {Science perspective} {Media}
• Griffin, A.S. & West, S.A. (2003) Kin discrimination and the benefit of helping in cooperatively breeding vertebrates. Science, 302, 634-636. {Media}
  
• Kiers, E.T., Rousseau, R.A., West, S.A. & Denison, R.F. (2003) Host sanctions and the legume-rhizobia mutualism. Nature, 425, 78-81.  {Media}
  
• Griffin, A.S. & West, S.A. (2002) Kin selection: fact and fiction. Trends in Ecology and Evolution, 17, 15-21.
• West, S.A., Pen, I. Griffin, A.S. (2002) Cooperation and competition between relatives. Science, 296, 72-75. {Supplementary Information} 
• West, S.A. & Buckling, A. (2003) Cooperation, virulence and siderophore production in bacterial parasites. Proceedings of the Royal Society London Series B 270, 37-44.
• West, S.A., Kiers, E.T., Pen, I. & Denison, R.F. (2002) Sanctions and mutualism stability: when should less beneficial mutualists be tolerated? Journal of Evolutionary Biology, 15, 830-837.
• West, S.A., Kiers, E.T., Simms, E.L. & Denison, R.F. (2002) Sanctions and mutualism stability: why do rhizobia fix Nitrogen? Proceedings of the Royal Society London Series B, 269, 685-694.
• West, S.A., Murray, M.G, Machado, C., Griffin, A.S. & Herre, E.A. (2001) Testing Hamilton’s rule with competition between relatives. Nature, 409, 510-513. {PDF of TREE commentary} {Media}
• Kiers, E.T., West, S.A. & Denison, R.F. (2002) Mediating mutualisms: Farm management practises and evolutionary changes in symbiont cooperation.  Journal of Applied Ecology, 39, 745-754.
• Pickering, J., Read, A.F., Guerrero, S. & West, S.A. (2000) Sex ratio and virulence in two species of lizard malaria parasites. Evolutionary Ecology Research, 2, 171-184.
• Herre, E.A. & West, S.A. (1997) Conflict of interest in a mutualism: documenting the elusive fig wasp/seed trade-off. Proceedings of the Royal Society London Series B, 264, 1501-1507.
• West, S.A. & Herre, E.A. (1994) The ecology of the New World fig-parasitising wasps Idarnes and implications for the evolution of the fig-pollinator mutualism. Proceedings of the Royal Society London Series B, 258, 67-72.