Local resource competition and the evolution of male-biased sex ratios

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

In many mammalian species, maturing males disperse from their natal groups, while females remain near their places of birth. If resources are limited locally, related females may be forced to compete with one another for access to resources, while mature males will compete primarily with unrelated individuals in non-natal groups. Clark (1978) suggested that under such circumstances the extent of competition among females could be reduced if females uniformly skewed the sex ratio of their offspring in favor of males. Skewed secondary sex ratios and investment patterns in galagos and red deer appear to be consistent with this hypothesis. Several authors have recently demonstrated that the evolution of skewed sex ratios may be influenced by population structure, and Wilson & Colwell (1981) have shown that male-biased sex ratios can evolve in structured haplo-diploid populations. Here, I construct an intrademic group selection model to simulate the effects of density-dependent mortality upon diploid populations structured much as Clark describes: males disperse, females remain near their female relatives, and local resource competition limits the size of local groups. The results confirm that male-biased sex ratios can evolve in a diploid species, even when groups are large and the skew in sex ratio is substantial.

Original languageEnglish (US)
Pages (from-to)203-213
Number of pages11
JournalJournal of Theoretical Biology
Volume108
Issue number2
DOIs
StatePublished - May 21 1984
Externally publishedYes

Fingerprint

Sex Ratio
Biased
sex ratio
Resources
Diploidy
diploidy
Galago
Population
Population Structure
Structured Populations
Deer
Selection Model
Cervus elaphus
Mortality
Skew
population structure
Dependent

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Applied Mathematics
  • Modeling and Simulation
  • Statistics and Probability
  • Medicine(all)

Cite this

Local resource competition and the evolution of male-biased sex ratios. / Silk, Joan.

In: Journal of Theoretical Biology, Vol. 108, No. 2, 21.05.1984, p. 203-213.

Research output: Contribution to journalArticle

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