The Unit of Selection in Viscous Populations and the Evolution of Altruism.

  title={The Unit of Selection in Viscous Populations and the Evolution of Altruism.},
  author={M vanBaalen and Rand},
  journal={Journal of theoretical biology},
  volume={193 4},
  • van Baalen MRand
  • Published 21 August 1998
  • Economics
  • Journal of theoretical biology
Group selection can overcome individual selection for selfishness and favour altruism if there is variation among the founders of the spatially distinct groups, and groups with many altruists become substantially larger (or exist longer) than groups with few. Whether altruism can evolve in populations that do not have an alternation of local population growth and global dispersal ("viscous populations") has been disputed for some time. Limited dispersal protects the altruists from the non… 

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Population viscosity and the evolution of altruism.

A class of models is presented in which population density is permitted to fluctuate, so that patches of altruists are supported at a higher density than patches of non-altruists, and under these conditions, population viscosity can support the selection of both weak and strong altruism.

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It is shown that a sterile worker caste can be selected for even under the simplest life-cycle assumptions, which has relevant consequences for the understanding of the evolution of altruism in social organisms, as many social insects are characterized by limited dispersal and significant genetic population structure.

The spatial spread of altruism versus the evolutionary response of egoists

  • J. Koella
  • Economics
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2000
An individual–based model of a viscous population shows that the ease with which altruism spreads in viscous populations is maintained despite countermeasures evolved by egoists.


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Selection for altruism through random drift in variable size populations

It is shown here that an altruistic allele extending the carrying capacity of the habitat can win by increasing the random drift of “selfish” alleles, based on the existence of random drift in variable size populations.

The robustness of the weak selection approximation for the evolution of altruism against strong selection

This work finds that the weak selection approximation is excellent even if selection is very strong, when either migration is much stronger than selection or when patches are large, and therefore provides a good approximation to understand the invasion of altruism in spatially structured population.

Altruism in viscous populations revisited: competition and altruism do not exactly cancel even in the island model

For Taylor’s model, the exact cancellation of the indirect fitness benefits of altruism by local competition requires the special case where Ne = N, a condition not often observed in nature.



The Effect of Stochastic Variation on Kin Selection in a Budding-Viscous Population

Computer simulations confirm that in populations with a viscous, permanent group structure, an altruist allele always fails in the absence of stochastic variation but follows Hamilton's rule if realistic levels of random variation are maintained.

Structured Demes and the Evolution of Group-Advantageous Traits

  • D. Wilson
  • Psychology
    The American Naturalist
  • 1977
Models are presented for warning cries and other donor-recipient relations, resource notification, the evolution of prudence in exploitation and interference competition, and the effect of differential trait-group extinction.


  • J. Kelly
  • Biology
    Evolution; international journal of organic evolution
  • 1992
It is demonstrated that a simple modification of the migration system employed in these studies decouples migration and population regulation thus favoring inter‐group selection and at least in some cases, restricted migration will facilitate the evolution of altruism.

Group Selection, Altruism, and Structured-Deme Models

  • L. Nunney
  • Psychology
    The American Naturalist
  • 1985
Structured-deme models are a valuable tool for analyzing local interactions and the resulting neighborhood selection; it is important to note, however, that if a model incorporates isolated trait groups, then within-group comparisons are entirely inappropriate for evaluating the fate of genotypes.

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  • J. Kelly
  • Environmental Science
    Theoretical population biology
  • 1994
A model that allows interaction, density regulation, and dispersion to operate over distinct spatial scales is presented that indicates that the appropriate scale for studying kin selection is determined by the spatial area over which the population is regulated.

The genetical evolution of social behaviour. I.

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  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1992
A general formulation of inclusive fitness is proposed which specifically accounts for competitive effects between relatives and shows that for an asexual population in a homogeneous inelastic environment, the inclusive fitness of a breeding female, under weak selection, is independent of her direct effect on the fitness of other individuals in the population.

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Selection of Intermediate Rates of Increase in Parasite-Host Systems

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