Frequency-dependent sexual selection with respect to progeny survival is consistent with predictions from rock-paper-scissors dynamics in the European common lizard

Abstract

Genetic polymorphism can be maintained over time by negative frequency-dependent (FD) selection induced by Rock-paper-scissors (RPS) social systems. RPS games produce cyclic dynamics, and have been suggested to exist in lizards, insects, isopods, plants, and bacteria. Sexual selection is predicted to accentuate the survival of the future progeny during negative FD survival selection. More specifically, females are predicted to select mates that produce progeny genotypes that exhibit highest survival during survival selection imposed by adult males. However, no empirical evidence demonstrates the existence of FD sexual selection with respect to fitness payoffs of genetic polymorphisms. Here we tested this prediction using the common lizard Zootoca vivipara, a species with three male color morphs (orange, white, yellow) that exhibit morph frequency cycles. In a first step we tested the congruence of the morph frequency change with the predicted change in three independent populations, differing in male color morph frequency and state of the FD morph cycle. Thereafter we ran standardized sexual selection assays in which we excluded alternative mechanisms that potentially induce negative FD selection, and we quantified inter-sexual behavior. The patterns of sexual selection and the observed behavior were in line with context-dependent female mate choice and male behavior played a minor role. Moreover, the strength of the sexual selection was within the magnitude of selection required to produce the observed 3-4-year and 6-8 year morph frequency cycles at low and high altitudes, respectively. In summary, the study provides the first experimental evidence that underpins the crucial assumption of the RPS games suggested to exist in lizards, insects, isopods, and plants; namely, that sexual selection produces negative-FD selection. This indicates that sexual selection, in our study exert by females, might be a crucial driver of the maintenance of genetic polymorphisms.

Climate Effects on Growth, Body Condition, and Survival Depend on the Genetic Characteristics of the Population

“…Morphs can be classified using two color scores (namely, o and w score), which account for the number of putative color alleles (o score: 2 p oo; 1 p yo, wo; 0 p yy, wy, and ww; w score: 2 p ww; 1 p wy, wo; 0 p yy, yo, and oo; Sinervo et al 2007). Color morphs differ visually and are determined by differential carotenoid deposition (San-Jose et al 2012, which is unaffected by carotenoid ingestion (Fitze et al 2009;San-Jose et al 2013), in line with genetic determination of color morphs (Fitze et al 2014). Male color morphs exhibit alternative behavioral strategies and periodic frequency cycles (Sinervo et al 2007).…”

“…Females have whitish bellies and exhibit context-dependent mate choice (Fitze et al 2010). They choose mate partners to maximize offspring survival under the predominant adult color morph frequency in autumn (Sinervo et al 2007;Fitze et al 2014;San-Jose et al 2014).…”

“…The common lizard is a highly hydrophilic species, and populations exhibit a pronounced age structure (Avery 1975;Heulin 1985). Adult males exhibit a genetic color polymorphism (San-Jose et al 2012Fitze et al 2014), and the polymorphism frequency reflects the genetic characteristics of the populationthat is, the genotype frequencies at the morph loci (at the locus or loci contributing to color morph) and all linked loci (Sinervo et al 2007(Sinervo et al , 2008. Zootoca vivipara occurrence is strongly associated with humidity (Pilorge 1987;Ceirans 2007;Peñalver-Alcázar et al 2016), and climate change models predict a global increase in overall precipitation, mean and extreme temperature, and alteration of local precipitation patterns (IPCC 2013).…”

Climate suggests environment‐dependent selection on lizard colour morphs

“…However, if a frequency‐dependent selection system was true for this species, the system underlying this polymorphism should be more complicated. Clarifying the existence of cyclic dynamics in morph composition, and their potential effect on the system (Fitze, González‐Jimena, San José, Heulin, & Sinervo, ; Le Rouzic, Hansen, Gosden, & Svensson, ; Sinervo et al., ; Svensson, Abbott, & Härdling, ; Takahashi, Kagawa, Svensson, & Kawata, ), will also be considered in future research.…”

Intensity of male‐male competition predicts morph diversity in a color polymorphic lizard

“…A large body of evidence demonstrates that color polymorphisms are associated with alternative reproductive tactics in some lizards (Sinervo and Lively ; Sinervo and Svensson ; Lattanzio and Miles ; also in lacertids, Fitze et al. ; San José et al. ).…”