Trait differences among discrete morphs of a color polymorphic lizard,Podarcis erhardii

Abstract

Color polymorphism defies evolutionary expectations as striking phenotypic variation is maintained within a single species. Color and other traits mediate social interactions, and stable polymorphism within a population is hypothesized to be related to correlational selection of other phenotypic traits among color morphs. Here, we report on a previously unknown throat color polymorphism in the Aegean Wall Lizard (Podarcis erhardii) and examine morph-correlated differences in traits important to social behavior and communication: maximum bite force capacity and chemical signal profile. We find that both sexes of P. erhardii have three color morphs: orange, yellow, and white. Moreover, orange males are significantly larger and tend to bite harder than yellow and white males. Although the established color polymorphism only partially matches the observed intraspecific variation in chemical signal signatures, the chemical profile of the secretions of orange males is significantly divergent from that of white males. Our findings suggest that morph colors are related to differences in traits that are crucial for social interactions and competitive ability, illustrating the need to look beyond color when studying polymorphism evolution.

Color Polymorphism is a Driver of Diversification in the Lizard Family Lacertidae

“…Examination of all extant taxa, including species lacking available genetic data and not represented in our phylogeny, was necessary to account for trait estimation proportions downstream in our state-dependent speciation and extinction (SSE) models. We scored color polymorphism from several georeferenced sources to ensure taxonomic validity, including online databases with photographs ( www.inaturalist.org , www.lacerta.de ), scientific literature ( Huyghe et al 2009a , 2009b ; López et al 2009 ; Runemark et al 2010 ; Brock et al 2020 ), and field guides ( Valakos et al 2008 ; Speybroeck et al 2016 ). We a priori restricted our investigation to color polymorphism defined as species with multiple coexisting color morphs in the same geographic location.…”

“…Biologists have identified a similar throat color polymorphism in several genera across the family Lacertidae ( Fig. 1 ), including Iberolacerta monticola ( López et al 2009 ), Podarcis species ( P. erhardii , Brock et al 2020 ; P. gaigeae , Runemark et al 2010 ; P. melisellensis , Huyghe et al 2009a , 2009b ; P. muralis , Pérez i de Lanuza et al 2019 ), and Zootoca vivipara ( Vercken and Clobert 2008 ). The Lacertidae is the most speciose family of squamates in the Western Palearctic comprising around 320 species distributed across Africa, Asia, and Europe ( Arnold et al 2007 ).…”

“… Throat color polymorphism in Podarcis erhardii ( Brock et al 2020 ), a Mediterranean lacertid species. In lacertid lizards, 43 species spanning several genera exhibit a similar color polymorphism.…”

“…Lizards from at least seven different families have repeatedly and independently evolved a similar color polymorphism on the head, throat, and/or ventral region ( Stuart-Fox et al 2020 ), which makes this trait ideal for comparative analysis. The lizard family Lacertidae ( Oppel 1811 ) is an excellent group for a comparative study on the evolution of color polymorphism as the group is relatively speciose and multiple species spanning several genera are known to be color polymorphic ( Vercken and Clobert 2008 ; Huyghe et al 2009a , 2009b ; Runemark et al 2010 ; Brock et al 2020 ). Biologists have identified a similar throat color polymorphism in several genera across the family Lacertidae ( Fig.…”

Multivariate Characterization of Morpho-biometric Traits of Indigenous Helmeted Guinea Fowl (Numida meleagris) in Nigeria

“…Colour polymorphism defies evolutionary expectations as a single species may maintain a striking phenotypic variation [52]. The present variant phenotypes may be due to polymorphism [53], and might have evolved in local guinea fowls as adaptive measures for survival under varied environmental conditions.…”