ASSORTATIVE MATING PREFERENCES AMONG HYBRIDS OFFERS A ROUTE TO HYBRID SPECIATION

Abstract The theory of ecological speciation suggests that assortative mating evolves most easily when mating preferences are directly linked to ecological traits that are subject to divergent selection. Sensory adaptation can play a major role in this process, because selective mating is often mediated by sexual signals: bright colours, complex song, pheromone blends and so on. When divergent sensory adaptation affects the perception of such signals, mating patterns may change as an immediate consequence. Alternatively, mating preferences can diverge as a result of indirect effects: assortative mating may be promoted by selection against intermediate phenotypes that are maladapted to their (sensory) environment. For Lake Victoria cichlids, the visual environment constitutes an important selective force that is heterogeneous across geographical and water depth gradients. We investigate the direct and indirect effects of this heterogeneity on the evolution of female preferences for alternative male nuptial colours (red and blue) in the genus Pundamilia. Here, we review the current evidence for divergent sensory drive in this system, extract general principles, and discuss future perspectives.

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Assortative mating and the role of phenotypic plasticity in male competition: implications for gene flow among host-associated parasitoid populations

Biology Letters ◽

10.1098/rsbl.2008.0369 ◽

2008 ◽

Vol 4 (5) ◽

pp. 508-511 ◽

Cited By ~ 5

Author(s):

Lee M Henry

Keyword(s):

Gene Flow ◽

Phenotypic Plasticity ◽

Local Adaptation ◽

Assortative Mating ◽

Host Species ◽

Relative Size ◽

Mating Preference ◽

Adult Males ◽

Mating Preferences

Local adaptation is promoted when habitat or mating preferences reduce gene flow between populations. However, gene flow is not only a function of dispersal but also of the success of migrants in their new habitat. In this study I investigated mating preference in conjunction with phenotypic plasticity using Aphidius parasitoids adapted to different host species. Males actively attempted to assortatively mate, but actual mating outcomes were strongly influenced by the relative size of the adult males. Results are discussed in the context of assortative mating in combination with the success of migrant males in mitigating gene flow between host-associated parasitoid populations.

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Differences in male coloration are predicted by divergent sexual selection between populations of a cichlid fish

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2016.0172 ◽

2016 ◽

Vol 283 (1830) ◽

pp. 20160172 ◽

Cited By ~ 22

Author(s):

O. M. Selz ◽

R. Thommen ◽

M. E. R. Pierotti ◽

J. M. Anaya-Rojas ◽

O. Seehausen

Keyword(s):

Sexual Selection ◽

Mate Choice ◽

Assortative Mating ◽

Cichlid Fish ◽

Female Mate Choice ◽

Population Based ◽

Mating Preferences ◽

Female Mating ◽

Female Mating Preferences ◽

Male Coloration

Female mating preferences can influence both intraspecific sexual selection and interspecific reproductive isolation, and have therefore been proposed to play a central role in speciation. Here, we investigate experimentally in the African cichlid fish Pundamilia nyererei if differences in male coloration between three para-allopatric populations (i.e. island populations with gene flow) of P. nyererei are predicted by differences in sexual selection by female mate choice between populations . Second, we investigate if female mating preferences are based on the same components of male coloration and go in the same direction when females choose among males of their own population, their own and other conspecific populations and a closely related para-allopatric sister-species, P. igneopinnis . Mate-choice experiments revealed that females of the three populations mated species-assortatively, that populations varied in their extent of population-assortative mating and that females chose among males of their own population based on different male colours. Females of different populations exerted directional intrapopulation sexual selection on different male colours, and these differences corresponded in two of the populations to the observed differences in male coloration between the populations. Our results suggest that differences in male coloration between populations of P. nyererei can be explained by divergent sexual selection and that population-assortative mating may directly result from intrapopulation sexual selection.

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