The ability of feathers to perform many functions either simultaneously or at different times
throughout the year or life of a bird is integral to the evolutionary history of birds. Many …

Sexual selection is a key component of evolutionary biology. However, from the very
formulation of sexual selection by Darwin, the nature and extent of sexual selection have …

Human cooperation is highly unusual. We live in large groups composed mostly of non-
relatives. Evolutionists have proposed a number of explanations for this pattern, including …

While it is widely acknowledged that Darwin's descriptions of females were gender-biased,
gender bias in current sexual selection research is less recognized. An examination of the …

Bird song has historically been considered an almost exclusively male trait, an observation
fundamental to the formulation of Darwin's theory of sexual selection. Like other male …

Acoustic signals mediate mate choice, resource defense, and species recognition in a broad
range of taxa. It has been proposed, therefore, that divergence in acoustic signals plays a …

During the latter half of the last century, evidence of reproductive competition between males
and male selection by females led to the development of a stereotypical view of sex …

Animal coloration is one of the most conspicuous aspects of human-perceived organismal
diversity, yet also one of the least understood. In particular, explaining why species have …

Historically, bird song has been regarded as a sex-specific signalling trait; males sing to
attract females and females drive the evolution of signal exaggeration by preferring males …

For sexual selection to act on a given sex, there must exist variation in the reproductive
success of that sex as a result of differential access to mates or fertilisations. The …