Social evolution in the shadow of asymmetrical relatedness.
The persistence of altruism and spite remains an enduring problem of social evolution. It is well known that selection for these actions depends on the structure of the population-that is, on actors' genetic relationships to recipients and to the 'neighbourhood' upon which the effects of their actions redound. Less appreciated, however, is that population structure can cause genetic asymmetries between partners whereby the relatedness (defined relative to the neighbourhood) of an individual i to a partner j will differ from the relatedness of j to i. Here, we introduce a widespread mechanism of kin recognition to a model of dispersal in subdivided populations. In so doing, we uncover three remarkable consequences of asymmetrical relatedness. First, altruism directed at phenotypically similar partners evolves more easily among migrant than native actors. Second, spite directed at dissimilar partners evolves more easily among native than migrant actors. Third, unlike migrants, natives can evolve to pay costs that far outstrip those they spitefully impose on others. We find that the frequency of natives relative to migrants amplifies the asymmetries between them. Taken together, our results reveal differentiated patterns of 'phenocentrism' that readily arise from asymmetries of relatedness.
Department of Mathematics and Statistics, Queen's University, Kingston, Ontario, Canada K7L 3N6 Department of Psychology, Queen's University, Kingston, Ontario, Canada K7L 3N6 Program in Evolution and Governance, One Earth Future, Broomfield, CO 80021, USA dbkrupp@saltlab.org.
D B
DB
Krupp
Department of Mathematics and Statistics, Queen's University, Kingston, Ontario, Canada K7L 3N6 Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
Peter D
PD
Taylor
D000533:Altruism; D025041:Animal Migration; D000818:Animals; D001522:Behavior, Animal; D005075:Biological Evolution; D008954:Models, Biological; D012641:Selection, Genetic; D012919:Social Behavior
altruism; genetic relatedness; phenocentrism; spite