Data from: Loss of pigments in females is associated with sexual dichromatism in an ornamental trait

Sexual dichromatism is thought to evolve primarily as a function of sexual
selection, especially female choice. However other forces, from
sex-specific environmental conditions to social signaling in females, can
also generate color differences between sexes. We studied dewlap
dichromatism across 292 species of Anolis lizards. Dewlaps are colorful
throat ornaments found on males of most anole species but are also present
in females in many species. Although male and female dewlaps often have
similar coloration, in some species they are strikingly dichromatic. We
found that ornament color is labile and that dichromatism results from the
loss of costly pigments in females. This pattern could indicate a shift
towards signal loss in females; however, the secondary gains of female
dewlaps across the phylogeny suggest a potential advantageous function.
Possible mechanisms for female dewlap coloration include social selection,
non-sexual signaling, or detectability in different microhabitats (e.g.,
sensory drive). Female dewlap color overlap between co-occurring species
is both less than expected by chance overall and reduced in species-rich
communities, suggesting that dichromatism could be driven by competition.
Our results highlight that selection on females drives the observed
pattern of dichromatism, suggesting a potentially adaptive role for female
ornaments and emphasizing the need for additional work to understand
female ornament evolution.