There is increasing evidence1,2,3,4,5,6 for the process of sympatric speciation7,8, in which reproductive isolation of species occurs without physical isolation. Theoretical models9,10,11,12,13,14 have focused on disruptive natural selection as the crucial pressure for splitting a species. Here we report the theoretical finding that sympatric speciation may be caused by sexual selection even without disruptive natural selection. Specifically, we show that variation in a male secondary sexual character with two conspicuous extremes and the corresponding variance in female mating preference around no preference may jointly evolve into bimodal distributions with increasing modal divergence of the male and female traits, pulling a population apart into two prezygotically isolated populations. This mode of speciation, driven by two runaway processes15,16,17 in different directions, is promoted by an increase in the efficiency of females in discriminating among males or a decrease in the cost of male conspicuousness, indicating that sympatric speciation may occur more readily if barrier-free or predator-free conditions arise. Although even a slight cost of female preference would cancel the runaway process of sexual selection18, it would not cancel the divergent runaway processes of sympatric speciation.
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Turner,G. F. Speciation mechanism in Lake Malawi cichlids: A critical review. Arch. Hydrobiol. 44, 139–160 (1994).
Deutsch,J. C. Colour diversification in Malawi cichlids: evidence for adaptation, reinforcement or sexual selection? Biol. J. Linn. Soc. 62, 1–14 (1997).
Seehausen,O., Alphen,J. J. M. & Witte,F. Cichlid fish diversity threatened by eutrophication that curbs sexual selection. Science 277, 1808–1811 (1997).
Seehausen,O. & Alphen,J. J. M. The effect of male coloration on female mate choice in closely related Lake Victoria cichlids (Haplochromis nyererei complex). Behav. Ecol. Sociobiol. 42, 1–8 (1998).
Ritchie,M. G. & Phillips,S. D. F. in Endless Forms: Species and Speciation (eds Howard, D. J. & Berlocher, S. H.) 291–308 (Oxford Univ. Press, New York, 1998).
Albertson,R. C., Markert,J. A., Danley,P. D. & Kocher,T. D. Phylogeny of a rapidly evolving clade: The cichlid fishes of Lake Malawi, East Africa. Proc. Natl Acad. Sci. USA 96, 5107–5110 (1999).
Tauber,C. A. & Tauber,M. J. in Speciation and its Consequences (eds Otte, D. & Endler, J. A.) 307–344 (Sinauer, Sunderland, 1989).
Bush,G. L. Sympatric speciation in animals: new wine in old bottles. Trends Ecol. Evol. 9, 285–288 (1994).
Maynard Smith,J. Sympatric speciation. Am. Nat. 100, 637–650 (1966).
Tauber,G. A. & Tauber,M. J. A genetic model for sympatric speciation through habitat diversification and seasonal isolation. Nature 268, 702–705 (1977).
Doebeli,M. A quantitative genetic competition model for sympatric speciation. J. Evol. Biol. 9, 893–909 (1996).
Kawecki,T. J. Sympatric speciation via habitat specialization driven by deleterious mutations. Evolution 51, 1751–1763 (1997).
Kodrashov,A. S. & Kondrashov,F. A. Interactions among quantitative traits in the course of sympatric speciation. Nature 400, 351–354 (1999).
Dieckmann,U. & Doebeli,M. On the origin of species by sympatric speciation. Nature 400, 354–357 (1999).
Fisher,R. A. The Genetical Theory of Natural Selection (Clarendon, Oxford, 1930).
Lande,R. Models of speciation by sexual selection on polygenic traits. Proc. Natl Acad. Sci. USA 78, 3721–3725 (1981).
Seger,J. Unifying genetic models for the evolution of female choice. Evolution 39, 1185–1193 (1985).
Pomiankowski,A. The costs of choice in sexual selection. J. Theor. Biol. 128, 195–218 (1987).
Liou,L. W. & Price,T. D. Speciation by reinforcement of premating isolation. Evolution 48, 1451–1459 (1994).
Turner,G. F. & Burrows,M. T. A model of sympatric speciation by sexual selection. Proc. R. Soc. Lond. B 260, 287–292 (1995).
Pomiankowski,A., Iwasa,Y. & Nee,S. The evolution of costly mate preferences I. Fisher and biased mutation. Evolution 45, 1422–1430 (1991).
Iwasa,Y., Pomiankowski,A. & Nee,S. The evolution of costly mate preferences II. The ‘handicap’ principle. Evolution 45, 1431–1442 (1991).
Wu,G.-I. A stochastic simulation study on speciation by sexual selection. Evolution 39, 66–82 (1985).
M.H. thanks J. Lawton and the NERC Centre for Population Biology for their hospitality. This work was supported by a MESSC grant to M.H.
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Higashi, M., Takimoto, G. & Yamamura, N. Sympatric speciation by sexual selection. Nature 402, 523–526 (1999) doi:10.1038/990087
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