scholarly journals Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration

2015 ◽  
Vol 91 (2) ◽  
pp. 328-348 ◽  
Author(s):  
Alexandre Roulin
Keyword(s):  
Sexual Selection ◽  
Condition Dependence ◽  
Handicap Principle

scholarly journals Sexual selection and the handicap principle

Nature ◽  
1976 ◽  
Vol 261 (5557) ◽  
pp. 192-192
Author(s):  
John Krebs
Keyword(s):  
Sexual Selection ◽  
Handicap Principle

scholarly journals Sexual selection favours good or bad genes for pathogen resistance depending on males' pathogen exposure

2019 ◽  
Vol 286 (1902) ◽  
pp. 20190226 ◽  
Author(s):  
Patrick Joye ◽  
Tadeusz J. Kawecki
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Female Choice ◽  
Experimental Studies ◽  
Pathogen Resistance ◽  
Condition Dependence ◽  
Indirect Benefit ◽  
Intestinal Pathogen ◽  
Sexual Traits ◽  
Pathogen Exposure

Resistance to pathogens is often invoked as an indirect benefit of female choice, but experimental evidence for links between father's sexual success and offspring resistance is scarce and equivocal. Two proposed mechanisms might generate such links. Under the first, heritable resistance to diverse pathogens depends on general immunocompetence; owing to shared condition dependence, male sexual traits indicate immunocompetence independently of the male's pathogen exposure. By contrast, other hypotheses (e.g. Hamilton–Zuk) assume that sexual traits only reveal heritable resistance if the males have been exposed to the pathogen. The distinction between the two mechanisms has been neglected by experimental studies. We show that Drosophila melanogaster males that are successful in mating contests (one female with two males) sire sons that are substantially more resistant to the intestinal pathogen Pseudomonas entomophila —but only if the males have themselves been exposed to the pathogen before the mating contest. By contrast, sons of males sexually successful in the absence of pathogen exposure are less resistant than sons of unsuccessful males. We detected no differences in daughters’ resistance. Thus, while sexual selection may have considerable consequences for offspring resistance, these consequences may be sex-specific. Furthermore, contrary to the ‘general immunocompetence’ hypothesis, these consequences can be positive or negative depending on the epidemiological context under which sexual selection operates.

Amplifiers and the handicap principle in sexual selection: a different emphasis

1989 ◽  
Vol 235 (1281) ◽  
pp. 383-406 ◽  
Keyword(s):  
Sexual Selection ◽  
Genetic Association ◽  
Female Choice ◽  
Mating Success ◽  
Population Genetic ◽  
Genetic Model ◽  
Genetic Models ◽  
Handicap Principle ◽  
Resolution Power ◽  
Male Display

Population genetic models have shown that female choice is a potential cause of the evolution of male display. In these models the display is assumed to be the immediate object of female choice. Here I present an explicit genetic model that shows that male display can evolve as a consequence of female choice even when the display is not the immediate object of choice. When females initially base their preferences on the existence of variance in a cue that is correlated with male viability, a rare display can evolve to fixation if it amplifies the previously recognized differences in males, (i. e. if it increases the resolution power of females with respect to the original cue). By definition, amplifying displays (or amplifiers) increase mating success of the more viable males and decrease mating success of the less viable males. Therefore, the higher the frequency of the preferred, more viable males, the more likely it is that amplifiers will evolve to fixation. The evolution of an amplifier is further facilitated by a genetic association that is built up between the amplifier allele and the more viable allele. If the expression of the amplifier is limited to the more viable males, the amplifier will evolve to fixation provided only that the change in total fitness to the more viable males (higher mating success, lower viability), is positive.

scholarly journals Sexual Selection: Does Condition Dependence Fail to Resolve the ‘Lek Paradox’?

2007 ◽  
Vol 17 (9) ◽  
pp. R335-R337 ◽  
Author(s):  
Samuel Cotton ◽  
Andrew Pomiankowski
Keyword(s):  
Sexual Selection ◽  
Condition Dependence ◽  
Lek Paradox

Sexual dimorphism and condition dependence in the anal pad of the small Indian mongoose (Herpestes auropunctatus)

2015 ◽  
Vol 93 (5) ◽  
pp. 397-402
Author(s):  
M.A. Owen ◽  
D.C. Lahti
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Indirect Evidence ◽  
Condition Dependence ◽  
Secondary Sexual Traits ◽  
Herpestes Auropunctatus ◽  
Sexual Traits ◽  
Indian Mongoose ◽  
Small Indian Mongoose ◽  
Secondary Sexual

Secondary sexual traits tend to be sexually dimorphic, and theory predicts that such traits should also be condition-dependent in a sex-specific manner. We investigate these phenomena in a field study of the small Indian mongoose (Herpestes auropunctatus (Hodgson, 1836); formerly Herpestes javanicus (É. Geoffroy Saint-Hillaire, 1818)), in the first attempt at understanding secondary sexual traits and sexual selection in this species. Small Indian mongooses are solitary and nonterritorial, and they likely depend on chemical (scent) rather than visual or acoustic signals for communication. Additionally, they possess a fleshy projection around their anus, the anal pad, thought to aid in scent-marking. Our results revealed strong male-biased sexual dimorphism in mass, skull and body lengths, canine diameters, and anal pad area. After controlling for the influence of body length, males were 31% heavier and possessed anal pads that were 68% larger than females’. Additionally, anal pad size was positively related to body size in males but not in females and was condition-dependent in males but not in females. Taken together, our findings provide indirect evidence that the anal pad might have evolved, at least in part, via sexual selection.

scholarly journals Sexually selected skin colour is heritable and related to fecundity in a non-human primate

2014 ◽  
Vol 281 (1794) ◽  
pp. 20141602 ◽  
Author(s):  
Constance Dubuc ◽  
Sandra Winters ◽  
William L. Allen ◽  
Lauren J. N. Brent ◽  
Julie Cascio ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Individual Variation ◽  
Balancing Selection ◽  
Rhesus Macaques ◽  
Reproductive Rate ◽  
Condition Dependence ◽  
Selection Gradients ◽  
Sexually Selected Traits ◽  
Skin Redness ◽  
Selected Traits

Sexual selection promotes the prevalence of heritable traits that increase an individual's reproductive rate. Despite theoretically strong directional selection, sexually selected traits can show inter-individual variation. Here, we investigate whether red skin ornamentation, a rare example of a male mammalian trait involved in mate attraction, influences fecundity and is heritable in rhesus macaques ( Macaca mulatta ), and explore the mechanisms that are involved in maintaining trait variation. Interestingly, the trait is expressed by and is attractive to both sexes. We collected facial images of 266 free-ranging individuals and modelled skin redness and darkness to rhesus macaque vision. We used 20 years of genetic parentage data to calculate selection gradients on the trait and perform heritability analyses. Results show that males who were both darkly coloured and high-ranking enjoyed higher fecundity. Female skin redness was positively linked to fecundity, although it remains unclear whether this influences male selectiveness. Heritability explained 10–15% of the variation in redness and darkness, and up to 30% for skin darkness when sexes are considered separately, suggesting sex-influenced inheritance. Our results suggest that inter-individual variation is maintained through condition-dependence, with an added effect of balancing selection on male skin darkness, providing rare evidence for a mammalian trait selected through inter-sexual selection.

scholarly journals It is not always about body size: evidence of Rensch's rule in a male weapon

2021 ◽  
Vol 17 (6) ◽  
pp. 20210234
Author(s):  
Glauco Machado ◽  
Bruno A. Buzatto ◽  
Diogo S. M. Samia
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Potential Role ◽  
Empirical Studies ◽  
Condition Dependence ◽  
Rensch’S Rule ◽  
Evolutionary Pattern ◽  
Rensch's Rule ◽  
Original Proposal

In many species, sexual dimorphism increases with body size when males are the larger sex but decreases when females are the larger sex, a macro-evolutionary pattern known as Rensch's rule (RR). Although empirical studies usually focus exclusively on body size, Rensch's original proposal included sexual differences in other traits, such as ornaments and weapons. Here, we used a clade of harvestmen to investigate whether two traits follow RR: body size and length of the fourth pair of legs (legs IV), which are used as weapons in male–male fights. We found that males were slightly smaller than females and body size did not follow RR, whereas legs IV were much longer in males and followed RR. We propose that sexual selection might be stronger on legs IV length than on body size in males, and we discuss the potential role of condition dependence in the emergence of RR.

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