An analytically tractable model for competitive speciation

Pleuni S. Pennings, Michael Kopp, Géza Meszéna, Ulf Dieckmann, Joachim Hermisson

Research output: Contribution to journalArticle

63 Citations (Scopus)


Several recent models have shown that frequency-dependent disruptive selection created by intraspecific competition can lead to the evolution of assortative mating and, thus, to competitive sympatric speciation. However, since most of these results rely on limited numerical analyses, their generality has been debated. Here,we consider one of the standard models (the so-called Roughgarden model) with a simplified genetics where the selected trait is determined by a single diallelic locus. This model is sufficiently complex to maintain key properties of the general multilocus case but simple enough to allow for comprehensive analytical treatment by means of invasion fitness arguments. Depending on (1) the strength and (2) the shape of stabilizing selection, (3) the strength and (4) the shape of pairwise competition, (5) the shape of the mating function, and (6) whether assortative mating leads to sexual selection, we find five different evolutionary regimes. In one of these regimes, complete reproductive isolation can evolve through arbitrarily small steps in the strength of assortative mating. Our approach provides a mechanistic understanding of several phenomena that have been found in previous models. The results demonstrate how even in a simple model, the evolutionary outcome depends in a complex way on ecological and genetic parameters.

Original languageEnglish
Pages (from-to)E44-E71
JournalAmerican Naturalist
Issue number1
Publication statusPublished - Jan 1 2008


  • Assortative mating
  • Frequency-dependent selection
  • Invasion fitness
  • Population-genetic model
  • Sexual selection
  • Sympatric speciation

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Fingerprint Dive into the research topics of 'An analytically tractable model for competitive speciation'. Together they form a unique fingerprint.

  • Cite this

    Pennings, P. S., Kopp, M., Meszéna, G., Dieckmann, U., & Hermisson, J. (2008). An analytically tractable model for competitive speciation. American Naturalist, 171(1), E44-E71.