The hypothesis that ornaments can honestly signal quality only if their expression is
condition-dependent has dominated the study of the evolution and function of colour traits …

Colour polymorphisms (CP's) continue to be of interest to evolutionary biologists because of
their general tractability, importance in studies of selection and potential role in speciation …

Female ornaments are often reduced, male-like traits. Although these were long perceived
as non-functional, it is now broadly accepted that female ornaments can be adaptive …

Melanins are the ubiquitous pigments distributed in nature. They are one of the main
pigments responsible for colors in living cells. Birds are among the most diverse animals …

Establishing the links between phenotype and genotype is of great importance for resolving
key questions about the evolution, maintenance and adaptive function of phenotypic …

Evolutionary psychology suggests that certain human beauty standards have evolved to
provide reliable cues of fertility and health. Hence, preferences for some physical …

The handicap principle of sexual selection theory states that colourful phenotypic traits
signal aspects of individual quality because only individuals in prime condition can afford to …

The melanocortin system is implicated in the expression of many phenotypic traits. Activation
of the melanocortin MC1 receptor by melanocortin hormones induces the production of …

Ecological parameters vary in space, and the resulting heterogeneity of selective forces can
drive adaptive population divergence. Clinal variation represents a classical model to study …

Local adaptation is a major mechanism underlying the maintenance of phenotypic variation
in spatially heterogeneous environments. In the barn owl (Tyto alba), dark and pale reddish …