Space use and genetic structure do not maintain color polymorphism in a species with alternative behavioral strategies

Abstract

Space use including territoriality and spatial arrangement within a population can reveal important information on the nature, dynamics, and evolutionary maintenance of alternative strategies in color polymorphic species. Despite the prevalence of color polymorphic species as model systems in evolutionary biology, the interaction between space use and genetic structuring of morphs within populations has rarely been examined. Here, we assess the spatial and genetic structure of male throat color morphs within a population of the tawny dragon lizard, Ctenophorus decresii. Male color morphs do not differ in morphology but differ in aggressive and antipredator behaviors as well as androgen levels. Despite these behavioral and endocrine differences, we find that color morphs do not differ in territory size, with their spatial arrangement being essentially random with respect to each other. There were no differences in genetic diversity or relatedness between morphs; however, there was significant, albeit weak, genetic differentiation between morphs, which was unrelated to geographic distance between individuals. Our results indicate potential weak barriers to gene flow between some morphs, potentially due to nonrandom pre‐ or postcopulatory mate choice or postzygotic genetic incompatibilities. However, space use, spatial structure, and nonrandom mating do not appear to be primary mechanisms maintaining color polymorphism in this system, highlighting the complexity and variation in alternative strategies associated with color polymorphism.

No evidence for differential sociosexual behavior and space use in the color morphs of the European common wall lizard (Podarcis muralis)

“…This dynamic gives rise to periodic oscillations in the relative frequencies of U. stansburiana male color morphs, in a cyclical “rock–paper–scissors” (RPS) game whereby each color morph, when predominant, is vulnerable to invasion by another color morph (Sinervo & Calsbeek, 2006; Sinervo & Lively, 1996). These results sparked a proliferation of studies aimed at detecting similar differences in reproductive behavior among the numerous species of lizards with color polymorphism (Bastiaans, Morinaga, Castañeda Gaytán, Marshall, & Sinervo, 2013; Fernández et al., 2018; Huyghe, Herrel, Adriaens, Tadić, & Van damme, 2009; Huyghe, Vanhooydonck, Herrel, Tadic, & Van Damme, 2007; Olsson, Healey, & Astheimer, 2007; Olsson, Stuart‐Fox, & Ballen, 2013; San‐Jose, Peñalver‐Alcázar, Milá, Gonzalez‐Jimena, & Fitze, 2014; Yewers, Pryke, & Stuart‐Fox, 2016; Yewers, Stuart‐Fox, & Mclean, 2018). For a number of reasons, morph‐specific ARS, morph fluctuations, and rock–paper–scissors dynamics similar to those described in Uta stansburiana have been predicted to occur in Eurasian lacertids, particularly in wall lizards (genus Podarcis , family Lacertidae; Sinervo et al., 2007; Calsbeek, Hasselquist, & Clobert, 2010; Mangiacotti et al., 2019).…”

Divergent male and female mate preferences do not explain incipient speciation between lizard lineages

“…2012 ; Ramos and Peters 2016 ). Males are polygynous with territories encompassing the home ranges of one or more females ( Yewers et al. 2018 ); thus, a male’s ability to defend a territory likely influences reproductive success.…”