Logo of geneticsGeneticsCurrent IssueInformation for AuthorsEditorial BoardSubscribeSubmit a Manuscript
Genetics. 1997 Feb; 145(2): 493–504.
PMCID: PMC1207813

The Spread of an Advantageous Allele across a Barrier: The Effects of Random Drift and Selection against Heterozygotes


A local barrier to gene flow will delay the spread of an advantageous allele. Exact calculations for the deterministic case show that an allele that is favorable when rare is delayed very little even by a strong barrier: its spread is slowed by a time proportional to log ((B/σ) &2S)/S, where B is the barrier strength, σ the dispersal range, and fitnesses are 1:1 + S:1 + 2S. However, when there is selection against heterozygotes, such that the allele cannot increase from low frequency, a barrier can cause a much greater delay. If gene flow is reduced below a critical value, spread is entirely prevented. Stochastic simulations show that with additive selection, random drift slows down the spread of the allele, below the deterministic speed of σ &2S. The delay to the advance of an advantageous allele caused by a strong barrier can be substantially increased by random drift and increases with B/(2Sρσ(2)) in a one-dimensional habitat of density ρ. However, with selection against heterozygotes, drift can facilitate the spread and can free an allele that would otherwise be trapped indefinitely by a strong barrier. We discuss the implications of these results for the evolution of chromosome rearrangements.

Full Text

The Full Text of this article is available as a PDF (1.1M).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Barton NH. The effects of linkage and density-dependent regulation on gene flow. Heredity (Edinb) 1986 Dec;57(Pt 3):415–426. [PubMed]
  • Barton NH, Rouhani S. The frequency of shifts between alternative equilibria. J Theor Biol. 1987 Apr 21;125(4):397–418. [PubMed]
  • Capanna E, Corti M, Mainardi D, Parmigiani S, Brain PF. Karyotype and intermale aggression in wild house mice: ecology and speciation. Behav Genet. 1984 May;14(3):195–208. [PubMed]
  • Capanna E, Gropp A, Winking H, Noack G, Civitelli MV. Robertsonian metacentrics in the mouse. Chromosoma. 1976 Nov 29;58(4):341–353. [PubMed]
  • Charlesworth D, Charlesworth B. Sex differences in fitness and selection for centric fusions between sex-chromosomes and autosomes. Genet Res. 1980 Apr;35(2):205–214. [PubMed]
  • Davisson MT, Akeson EC. Recombination suppression by heterozygous Robertsonian chromosomes in the mouse. Genetics. 1993 Mar;133(3):649–667. [PMC free article] [PubMed]
  • Epperson BK. Spatial and space-time correlations in systems of subpopulations with stochastic migration. Theor Popul Biol. 1994 Oct;46(2):160–197. [PubMed]
  • Nagylaki T. Clines with variable migration. Genetics. 1976 Aug;83(4):867–886. [PMC free article] [PubMed]
  • Slatkin M, Charlesworth D. The spatial distribution of transient alleles in a subdivided population: a simulation study. Genetics. 1978 Aug;89(4):793–810. [PMC free article] [PubMed]
  • Viroux MC, Bauchau V. Segregation and fertility in Mus musculus domesticus (wild mice) heterozygous for the Rb(4.12) translocation. Heredity (Edinb) 1992 Feb;68(Pt 2):131–134. [PubMed]
  • Wilson AC, Sarich VM, Maxson LR. The importance of gene rearrangement in evolution: evidence from studies on rates of chromosomal, protein, and anatomical evolution. Proc Natl Acad Sci U S A. 1974 Aug;71(8):3028–3030. [PMC free article] [PubMed]

Articles from Genetics are provided here courtesy of Genetics Society of America


Save items

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...