The ecological stage changes benefits of mate choice and drives preference divergence: Ecological stage alters choice benefits

Author ORCID Identifier

Jennifer Koop:https://orcid.org/0000-0002-5332-3618

Publication Title

Philosophical Transactions of the Royal Society B: Biological Sciences

ISSN

09628436

E-ISSN

14712970

Document Type

Article

Abstract

Preference divergence is thought to contribute to reproductive isolation. Ecology can alter the way selection acts on female preferences, making them most likely to diverge when ecological conditions vary among populations. We present a novel mechanism for ecologically dependent sexual selection, termed 'the ecological stage' to highlight its ecological dependence. Our hypothesized mechanism emphasizes that males and females interact over mating in a specific ecological context, and different ecological conditions change the costs and benefits of mating interactions, selecting for different preferences in distinct environments and different male traits, especially when traits are condition dependent. We test key predictions of this mechanism in a sympatric three-spine stickleback species pair. We used a maternal half-sib split-clutch design for both species, mating females to attractive and unattractive males and raising progeny on alternate diets that mimic the specialized diets of the species in nature. We estimated the benefits of mate choice for an indicator trait (male nuptial colour) by measuring many fitness components across the lifetimes of both sons and daughters from these crosses. We analysed fitness data using a combination of aster and mixed models. We found that many benefits of mating with high-colour males depended on both species and diet. These results support the ecological stage hypothesis for sticklebacks. Finally, we discuss the potential role of this mechanism for other taxa and highlight its ability to enhance reproductive isolation as speciation proceeds, thus facilitating the evolution of strong reproductive isolation. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

Publication Date

8-31-2020

DOI

10.1098/rstb.2019.0546

PubMed ID

32654644

Keywords

aster modelling, mate choice, preference divergence, reproductive isolation, selection, speciation

Department

Department of Biological Sciences

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