Male ornaments can evolve through the exploitation of female perceptual biases such as those involved in responding to cues from food. This type of sensory exploitation may lead to confusion between the male signals and the cues that females use to find/recognize food. Such interference would be costly to females and may be one reason why females evolve resistance to the male ornaments. Using a...

Somatic deterioration in ageing animals may arise from allocation of resources to reproduction at the expense of repair and maintenance. Thus, accumulated reproductive effort is likely to progressively limit the expression of sexual ornaments at older ages. We analysed the effect of age and reproductive effort on the sexual attractiveness (foot colour) of male blue-footed boobies. Using a long-...

Personal ornaments play an important role in our understanding of human cultural and behavioral change during the Upper Paleolithic, providing insights into intangible aspects behavior. Some ornament forms are better studied than others, fox tooth ornaments, despite their frequent occurrence broad spatiotemporal span, relatively under-addressed. Here we present first comprehensive study 40 perf...

Females often possess ornaments that appear smaller and duller than homologous traits in males. These ornaments may arise as nonfunctional by-products of sexual selection in males and cause negative viability or fecundity selection in females in proportion to the cost of their production and maintenance. Alternatively, female ornaments may function as signals of quality that are maintained by s...

1. Exaggerated male ornaments often are hypothesised to increase predation risk due to reduced locomotor performance, yet empirical evidence supporting this proposition is equivocal. In part, current costs of ornaments may be difficult to detect in nature due to the evolution of compensatory mechanisms that offset detrimental effects. 2. The exaggerated eye stalks of male stalk-eyed flies incre...

Some of the most spectacular exaggerated sexual ornaments are carotenoid dependent. It has been suggested that such ornaments have evolved because carotenoid pigments are limiting for both signal expression and in their role as antioxidants and immunostimulants. An implicit assumption of this hypothesis is that males which can afford to produce more elaborate carotenoid-dependent displays are s...

Sexually selected ornaments and weapons are among nature's most extravagant morphologies. Both ornaments and weapons improve a male's reproductive success; yet, unlike ornaments that need only attract females, weapons must be robust and functional structures because they are frequently tested during male-male combat. Consequently, weapons are expected to be particularly costly to bear. Here, we...

The genetic basis of sexual dimorphisms is an intriguing problem of evolutionary genetics because dimorphic traits are limited to one sex. Such traits can arise genetically in two ways. First, the alleles that cause dimorphisms could be limited in expression to only one sex at their first appearance. Alternatively, dimorphism alleles could initially be expressed in both sexes, but subsequently ...