scholarly journals Preprint "The relative importance of intra- and intersexual selection on human male sexually dimorphic traits"

2017 ◽  
Author(s):  
Tobias Kordsmeyer ◽  
John Hunt ◽  
David Puts ◽  
Julia Ostner ◽  
Lars Penke
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Female Choice ◽  
Mating Success ◽  
Upper Body ◽  
Sexual Attractiveness ◽  
Sexually Dimorphic ◽  
Physical Strength ◽  
Human Male ◽  
Physical Dominance

Recent evidence suggests that in sexual selection on human males, intrasexual competition plays a larger role than female choice. In a sample of men (N = 164), we sought to provide further evidence on the effects of men’s physical dominance and sexual attractiveness on mating success and hence in sexual selection. Objective measures and subjective ratings of male sexually dimorphic traits purportedly under sexual selection (height, vocal and facial masculinity, upper body size from3D scans, physical strength, and baseline testosterone) and observer perceptions of physical dominance and sexual attractiveness based on self-presentation video recordings were assessed and associated with mating success (sociosexual behaviour and number of potential conceptions) in a partly longitudinal design. Results from structural equation models and selection analyses revealed that physical dominance, but not sexual attractiveness, predicted mating success. Physical dominance mediated associations of upper body size, physical strength, as well as vocal and facial physical dominance and attractiveness with mating success. These findings thus suggest a greater importance of intrasexual competition than female choice in human male sexual selection.

scholarly journals Sexual selection favours male parental care, when females can choose

2011 ◽  
Vol 279 (1734) ◽  
pp. 1784-1790 ◽  
Author(s):  
Suzanne H. Alonzo
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Female Choice ◽  
Mating Success ◽  
Current Theory ◽  
Sharp Contrast ◽  
Recent Theory ◽  
Extra Pair Paternity ◽  
Female Promiscuity ◽  
Male Care

Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.

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 on size and shape in Japanese beetles (Popillia japonica)

2020 ◽  
Vol 31 (4) ◽  
pp. 1073-1083 ◽  
Author(s):  
Clint D Kelly
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Mating Success ◽  
Insect Pest ◽  
Popillia Japonica ◽  
Female Size ◽  
Male Body ◽  
Japanese Beetle ◽  
Size Dimorphism ◽  
Selection For

Abstract The mobility hypothesis argues that species in which males compete for mates in scrambles often exhibit female-biased size dimorphism because smaller male body size should increase male mobility and success in searching for mates. Sexual dimorphism can be further exaggerated if fecundity or sexual selection concurrently selects for larger female size. Scramble competition can select for trait characteristics that optimize locomotion; for example, long and slender wings should be favored if aerial speed is important to mating success. I tested these predictions in the scrambling Japanese beetle (Popillia japonica), a female-biased size dimorphic insect pest that is invasive to North America. Multivariate selection analyses support the prediction that smaller body size and larger wings in males benefit their mating success. My analyses also revealed significant selection for larger wings in females but, contrary to prediction, direct sexual selection favors smaller body size in females. These results support the mobility hypothesis and partially explain the evolution of female-biased size dimorphism in this species. Sexual selection favored rounder bodies in females and more tapered bodies in males, whereas, in both sexes, the effect of wing shape appears less important to fitness than wing size.

scholarly journals Rapid courtship evolution in grouse (Tetraonidae): contrasting patterns of acceleration between the Eurasian and North American polygynous clades

2007 ◽  
Vol 274 (1613) ◽  
pp. 1079-1086 ◽  
Author(s):  
Allen Spaulding
Keyword(s):  
Sexual Selection ◽  
Mating Success ◽  
Male Mating ◽  
Sexually Dimorphic ◽  
Sexually Selected Traits ◽  
Species Pairs ◽  
Rapid Divergence ◽  
Nucleotide Divergence ◽  
Selected Traits ◽  
Dimorphic Species

Sexual selection is thought to be a powerful diversifying force, based on large ornamental differences between sexually dimorphic species. This assumes that unornamented phenotypes represent evolution without sexual selection. If sexual selection is more powerful than other forms of selection, then two effects would be: rapid divergence of sexually selected traits and a correlation between these divergence rates and variance in mating success in the ornamented sex. I tested for these effects in grouse (Tetraonidae). For three species pairs, within and among polygynous clades, male courtship characters had significantly greater divergence than other characters. This was most pronounced for two species in Tympanuchus . In the Eurasian polygynous clade, relative courtship divergence gradually increased with nucleotide divergence, suggesting a less dramatic acceleration. Increase in relative courtship divergence was associated with mating systems having higher variance in male mating success. These results suggest that sexual selection has accelerated courtship evolution among grouse, although the microevolutionary details appear to vary among clades.

scholarly journals SEXUAL SELECTION IN TOADS: THE ROLES OF FEMALE CHOICE AND MALE BODY SIZE

Evolution ◽  
1978 ◽  
Vol 32 (2) ◽  
pp. 264-270 ◽  
Author(s):  
Henry M. Wilbur ◽  
Daniel I. Rubenstein ◽  
Lincoln Fairchild
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Female Choice ◽  
Male Body ◽  
Male Body Size

scholarly journals Masculine voices signal men's threat potential in forager and industrial societies

2011 ◽  
Vol 279 (1728) ◽  
pp. 601-609 ◽  
Author(s):  
David A. Puts ◽  
Coren L. Apicella ◽  
Rodrigo A. Cárdenas
Keyword(s):  
Body Size ◽  
Acoustic Parameter ◽  
Acoustic Properties ◽  
Upper Body ◽  
Sexually Dimorphic ◽  
Sexual Dimorphisms ◽  
Body Strength ◽  
The Us ◽  
Upper Body Strength ◽  
Industrial Societies

Humans and many non-human primates exhibit large sexual dimorphisms in vocalizations and vocal anatomy. In humans, same-sex competitors and potential mates attend to acoustic features of male vocalizations, but vocal masculinity especially increases perceptions of physical prowess. Yet, the information content of male vocalizations remains obscure. We therefore examined relationships between sexually dimorphic acoustic properties and men's threat potential. We first introduce a new measure of the structure of vocal formant frequencies, ‘formant position’ ( P f ), which we show is more sexually dimorphic and more strongly related to height than is the most widely used measure of formant structure, ‘formant dispersion’, in both a US sample and a sample of Hadza foragers from Tanzania. We also show large sexual dimorphisms in the mean fundamental frequency ( F 0 ) and the within-utterance standard deviation in F 0 ( F 0 − s.d.) in both samples. We then explore relationships between these acoustic parameters and men's body size, strength, testosterone and physical aggressiveness. Each acoustic parameter was related to at least one measure of male threat potential. The most dimorphic parameters, F 0 and P f , were most strongly related to body size in both samples. In the US sample, F 0 predicted testosterone levels, P f predicted upper body strength and F 0 − s.d. predicted physical aggressiveness.

scholarly journals Female preference for multi-modal courtship: multiple signals are important for male mating success in peacock spiders

2015 ◽  
Vol 282 (1820) ◽  
pp. 20152222 ◽  
Author(s):  
Madeline B. Girard ◽  
Damian O. Elias ◽  
Michael M. Kasumovic
Keyword(s):  
Sexual Selection ◽  
Mating Success ◽  
Female Preference ◽  
Male Mating ◽  
Sexually Dimorphic ◽  
Complex Signals ◽  
Sexually Selected Traits ◽  
Redundant Signal ◽  
Multiple Messages ◽  
Selected Traits

A long-standing goal for biologists has been to understand how female preferences operate in systems where males have evolved numerous sexually selected traits. Jumping spiders of the Maratus genus are exceptionally sexually dimorphic in appearance and signalling behaviour. Presumably, strong sexual selection by females has played an important role in the evolution of complex signals displayed by males of this group; however, this has not yet been demonstrated. In fact, despite apparent widespread examples of sexual selection in nature, empirical evidence is relatively sparse, especially for species employing multiple modalities for intersexual communication. In order to elucidate whether female preference can explain the evolution of multi-modal signalling traits, we ran a series of mating trials using Maratus volans . We used video recordings and laser vibrometry to characterize, quantify and examine which male courtship traits predict various metrics of mating success. We found evidence for strong sexual selection on males in this system, with success contingent upon a combination of visual and vibratory displays. Additionally, independently produced, yet correlated suites of multi-modal male signals are linked to other aspects of female peacock spider behaviour. Lastly, our data provide some support for both the redundant signal and multiple messages hypotheses for the evolution of multi-modal signalling.

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