Male competition and speciation: Expanding our framework for speciation by sexual selection

• Type of Material: Article
• Authors: Alycia C. R. Lackey, Binghamton University; Michael Martin, Emory University; Robin M. Tinghitella, University of Denver
• Language: English
• Date: 2018-02-01
• Publisher: Oxford Academic
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) (2018). Published by Oxford University Press.
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1093/cz/zoy009
• Title of Journal or Parent Work: Current Zoology
• Volume: 64
• Issue: 1
• Start Page: 69
• End Page: 73
• Grant/Funding Information: The invitation to guest edit this special column resulted from a symposium co-organized by ACRL, MDM, and RMT at the 2016 congress of the International Society for Behavioral Ecology, and travel expenses for all authors were supported in part by the National Science Foundation (IOS-1637252).; While guest editing this special column, ACRL was supported by NSF (DEB-1638997) and the Watershed Studies Institute at Murray State University.; RMT was supported by NSF (IOS-1601531) and the University of Denver's Office of the Associate Provost of Research.
• Keywords: Genotype; Speciation; Evolutionary change; Mating preference; Zoology; Sexual selection; phenotypic adaptation; Population genetics; Natural selection; Male competition
• Research Categories: Biology, Zoology; Biology, Genetics; Biology, General

Abstract

Sexual selection is a powerful source of rapid evolutionary change, and there is a long-standing hypothesis that it can cause reproductive isolation. However, our understanding of speciation by sexual selection is largely limited to mechanisms by which sexual selection via female mate choice can drive divergence (i.e., when male mating signals and female preferences for those signals diversify; Panhuis et al. 2001; Maan and Seehausen 2011). Male competition for mates—Darwin’s second mechanism of sexual selection—can also favor rapid and dramatic phenotypic and genotypic changes, yet it has been all but overlooked in speciation research (Darwin 1859, 1871; Seehausen and Schluter 2004; Qvarnström et al. 2012; Tinghitella et al. forthcoming). Evidence suggests that male competition is capable of driving divergence and potentially contributing to the speciation process. First, male competition can generate strong selection that favors divergent phenotypes within and between populations. In some mating systems, male competition primarily determines mating success within populations (e.g., resource or harem defense polygyny; West-Eberhard 1983; Andersson 1994). In other mating systems, male competition acts as a filter, determining which males have access to females and, thus, the phenotypes available for female mate choice (Wong and Candolin 2005; Hunt et al. 2009). Further, the remarkable diversity in competitive phenotypes (i.e., weapons, agonistic signals, and competitive strategies; Seehausen and Schluter 2004; Grether et al. 2013; McCullough et al. 2014) likely results from population differences in selection generated by competition for mates. Second, it is well established that competition for resources can drive speciation via natural selection (Schluter 2001; Pfennig and Pfennig 2010). Competition for mating resources could have similar potential to shape the speciation process