Evolution of Coloration
Color has long been the focus of research on phenotypic diversity and trait evolution because of clear fitness benefits for reproduction (sexual selection) and survival (crypsis, aposematism, mimicry). Our work on color as an antipredator trait has spanned research on the role of color pattern for crypsis (Cox et al. 2020b), startle coloration (Cox et al. 2021), decoy coloration (Watson et al. 2012; Watson et al. 2019; Heninger et al. 2020), and mimicry (Davis Rabosky et al. 2016b). A major focus of color research in my laboratory is on the evolution of coral snake mimicry, which has revealed that spatiotemporal variability in selection drives color diversity (Cox and Davis Rabosky 2013; Davis Rabosky et al. 2016b), and that elevation can structure selection on coral snake color patterns (Wilson et al. 2022). This work has also revealed that genetic architecture of color can also impact diversity of non-mimetic traits (Curlis et al. 2021), which has led to a chaotic taxonomy in some snakes (Cox et al. 2018). We have found no evidence that a single gene or supergenes control mimetic coloration in a coral snake mimic (Cox et al. 2013), but rather that their coloration is controlled by two unlinked genes (Davis Rabosky et al. 2016a). Our future research is combining transcriptomics and genome sequencing to determine the genomic regions underlying mimetic traits to ask how selection at the phonotypic level is translated to genomic evolution.
My laboratory also studies the evolution of sexual signals, focusing on the dewlap of anole lizards. Dewlaps are an extendable throat signal that can be deployed to attract mates. Our work has revealed that dewlap development can be regulated by both testosterone and the environment (Cox et al. 2015; Curlis et al. 2017) and that dewlaps can impart a fitness cost of increased parasitism (Rosso et al. 2020). Our future work leverages our experimental island system in Panama and the slender anole lizard, which has a polymorphic dewlap. We have transplanted lizards of both dewlap morphs onto small islands in the Panama Canal that vary in predation pressure and light environment. We are currently tracking the evolution of dewlap characteristics in real time and using functional genomics with our recently published genome of the slender anole to discover the genetic locus underlying the polymorphism.
My laboratory also studies the evolution of sexual signals, focusing on the dewlap of anole lizards. Dewlaps are an extendable throat signal that can be deployed to attract mates. Our work has revealed that dewlap development can be regulated by both testosterone and the environment (Cox et al. 2015; Curlis et al. 2017) and that dewlaps can impart a fitness cost of increased parasitism (Rosso et al. 2020). Our future work leverages our experimental island system in Panama and the slender anole lizard, which has a polymorphic dewlap. We have transplanted lizards of both dewlap morphs onto small islands in the Panama Canal that vary in predation pressure and light environment. We are currently tracking the evolution of dewlap characteristics in real time and using functional genomics with our recently published genome of the slender anole to discover the genetic locus underlying the polymorphism.