How phenotypic matching based on neutral mating cues enables speciation in locally adapted populations

Sibly, R. M. ORCID: https://orcid.org/0000-0001-6828-3543, Pagel, M. ORCID: https://orcid.org/0000-0001-7287-8865, Curnow, R. N. and Edwards, J. (2019) How phenotypic matching based on neutral mating cues enables speciation in locally adapted populations. Ecology and Evolution, 9 (23). pp. 13506-13514. ISSN 2045-7758 doi: 10.1002/ece3.5806

Abstract/Summary

Maynard Smith's (American Naturalist, 1966, 100, 637) suggestion that in some cases a prerequisite for speciation is the existence of local ecological adaptations has not received much attention to date. Here, we test the hypothesis using a model like that of Maynard Smith but differing in the way animals disperse between niches. In previous studies, males disperse randomly between niches but females stay put in their natal niche. As a first step toward generalizing the model, we here analyze the case that equal proportions of the two sexes disperse between niches before breeding. Supporting Maynard Smith's (1966) hypothesis, we find that once local adaptations are established, a neutral mating cue at an independent locus can rapidly enable speciation in populations with a suitable mechanism for phenotype matching. We find that stable ecological polymorphisms are relatively insensitive to the strength of selection, but depend crucially on the extent of dispersal between niches, with a threshold of ~5% if population sizes in two niches are equal. At higher levels of dispersal, ecological differentiation is lost. These results contrast with those of earlier studies and shed light on why parapatric speciation is limited by the extent of gene flow. Our testable model provides a candidate explanation for the rapid speciation rates, diversity of appearance and occurrence of “species flocks” observed among some African cichlids and neotropical birds and may also have implications for the occurrence of punctuational change on phylogenies.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/87451
Identification Number/DOI	10.1002/ece3.5806
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
Publisher	Wiley
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