Within the lizard genus Ano/is, color variation in the dewlap, an important signaling trait, can indicate local adaptation or divergence between populations. Most research on anole dewlaps has taken aim at males rather than females. Despite several publications of unrelated lizard genera with links between female signal color polymorphisms and fecundity, variation in female anole dewlaps has received less inquiry. We compiled dewlap photographs of females from several populations of the Ano/is lemurinus group, characterized color variants through visual assignment, and tested for associations of dewlap color to body size and dewlap area. We describe the first case of polymorphic dewlap color in females and relatively monomorphic dewlap color in males within a group of anoles. Our survey found that female dewlap color variation in the group is more similar between geographically proximate northern populations of A. lemurinus and A. bicaonun than between populations ascribed to A. lemurinus from different regions. Additionally, we provide evidence that female body size in this group may correlate with dewlap coloration. Our findings support the need for further taxonomic research within the A. lemurinus group, as well as research into the potential mechanisms driving and maintaining color polymorphism in female signaling traits.

Sexually selected traits can be expected to increase in importance when the period of sexual behavior is constrained, such as in seasonally restricted breeders. Anolis lizard male dewlaps are classic examples of multifaceted signaling traits, with demonstrated intraspecific reproductive function reflected in courtship behavior. Fitch and Hillis found a correlation between dewlap size and seasonality in mainland Anolis using traditional statistical methods and suggested that seasonally restricted breeding seasons enhanced the differentiation of this signaling trait. Here, we present two tests of the Fitch–Hillis Hypothesis using new phylogenetic and morphological data sets for 44 species of Mexican Anolis. A significant relationship between dewlap size and seasonality is evident in phylogenetically uncorrected analyses but erodes once phylogeny is accounted for. This loss of strong statistical support for a relationship between a key aspect of dewlap morphology and seasonality also occurs within a species complex (A. sericeus group) that inhabits seasonal and aseasonal environments. Our results fail to support seasonality as a strong driver of evolution of Anolis dewlap size. We discuss the implications of our results and the difficulty of disentangling the strength of single mechanisms on trait evolution when multiple selection pressures are likely at play.

Lizards are a diverse reptile group with an ancient and global evolutionary history. Fossil lizards first appeared in North America during the Mesozoic. Many lizard lineages have inhabited North America throughout geologic time, including several lineages that are extinct, others that no longer occur on the continent, and many groups that are still there today. Lizards are currently found in a diverse range of habitats and in regions across the continent, including islands and human‐modified habitats. The modern lizard biota of North America contains diverse biogeographic and phylogenetic components along with the evolution of many distinctive behaviours, morphologies, and ecologies, including the evolution of venom, repeated limb loss, and ecological specialisations. Some lizards have been introduced to North America from elsewhere in the world or the continent, posing a potential problem for native biodiversity. Key Concepts North America contains an astounding diversity of lizards both in the modern biota and through geologic time. Although many fossil lizards are documented, there is still a lot to learn from the fossil record. Historic extirpations and extinctions of lizards are known and conservation efforts are needed to preserve lizard biodiversity. Biogeographic scenarios of lizards in North America are often disputed but are informed by fossil and molecular evidence. North American lizards have a diverse set of behavioural, morphological and ecological characteristics.

Sexually selected traits can be expected to increase in importance when the period of sexual behavior is constrained, such as in seasonally restricted breeders. Anolis lizard male dewlaps are classic examples of multifaceted signaling traits, with demonstrated reproductive function reflected in courtship behavior. Fitch and Hillis found a correlation between dewlap size and seasonality in mainland Anolis using traditional statistical methods. Here, we present two tests of the Fitch-Hillis Hypothesis using new phylogenetic and morphological data sets for 44 species of Mexican Anolis. A significant relationship between dewlap size and seasonality is evident in phylogenetically uncorrected analyses but erodes once phylogeny is accounted for. This loss of statistical support for a relationship between a key aspect of dewlap morphology and seasonality also occurs within a species complex (A. sericeus group) that inhabits seasonal and aseasonal environments. Our results fail to support seasonality as a strong driver of evolution of Anolis dewlap size. We discuss the implications of our results and the difficulty of disentangling the strength of single mechanisms on trait evolution when multiple selection pressures are likely at play.