A mixed model of the evolution of polygyny and sexual size dimorphism in mammals

@article{Cassini2019AMM,
  title={A mixed model of the evolution of polygyny and sexual size dimorphism in mammals},
  author={Marcelo H. Cassini},
  journal={Mammal Review},
  year={2019}
}
The theory of sexual selection is the most widely accepted theory explaining the evolution of mating systems and secondary sexual characters. Polygyny is the most common mating system in mammals, and there is a strong correlation between the degree of polygyny and the degree of sexual size dimorphism skewed towards males. Sexual selection theory posits that polygyny in mammals has evolved through direct, precopulatory, intrasexual selection in males, and that sexual size dimorphism is a result… 
Sexual size dimorphism and sexual selection in artiodactyls
TLDR
An interspecific test using the variance in genetic paternity as a proxy for the Is suggests that sexual selection may have played a role in the evolution of sexual size dimorphism in Artiodactyla.
Sexual size dimorphism and sexual selection in primates
TLDR
Results of this comparative analysis of sexual size dimorphism and sexual selection intensity in primates suggest that the use of intramale sexual selection theory to explain the evolution of polygyny and sexual Dimorphism in mammals should be reviewed, and that natural selection should be considered alongside sexual selection as an evolutionary driver.
Polygyny in the Era of Molecular Biology: Revisiting Bartholomew’s Model
  • M. Cassini
  • Biology
    Ethology and Behavioral Ecology of Otariids and the Odobenid
  • 2021
TLDR
Testing the literature on paternity for otariids found that size of harem did correlate with paternity by territorial males but the slope was significantly lower than expected from behavioural estimations; differences in paternity between territorial and satellites males were not statistically significant in most studies.
Sexual dimorphism in cranial shape and size in geomyoid rodents: multivariate and evolutionary perspectives
TLDR
The findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that, instead, it is the product of numerous evolutionary events.
Sexual aggression in mammals
In non‐human mammals, sexual conflict should be particularly intense because males rarely provide parental care. An expected consequence of sexual conflict is male aggression towards mates.
Sexual coercion in a natural mandrill population
TLDR
The nature of male coercive strategies in wild mandrills (Mandrillus sphinx) is investigated, finding support for all three predictions of the sexual coercion hypothesis, namely that male aggression specifically targets sexually receptive females, inflicts costs to these females, and increases male mating success in the long-term.
Contrasting selection pressure on body and weapon size in a polygynous megaherbivore
TLDR
Hippopotamus appear to be a rare example among ungulates whereby sexual selection favours increased weapon size over body mass, underlining the important role that species-specific ecology and physiology have in shaping SSD.
Killing conspecific adults in mammals
TLDR
The results indicate that the evolutionary pathways underlying the evolution of adulticide differ between sexes in mammals, and male and female adulticide mainly to defend offspring from infanticidal conspecifics.
Risk exposure trade-offs in the ontogeny of sexual segregation in Antarctic fur seal pups
TLDR
It is concluded that sex differences in habitat use can develop in a highly polygynous species prior to the onset of major sexual size dimorphism, which hints that these sex differences will increasingly diverge in later life.
Aging and Senescence across Reproductive Traits and Survival in Superb Fairy-Wrens (Malurus cyaneus)
TLDR
Examination of age-related changes in sex-specific survival, reproduction, and several components of reproduction using a long-term study of a cooperatively breeding songbird finds striking differences in aging and senescence patterns between survival and reproduction as well as between reproductive traits.
...
1
2
...

References

SHOWING 1-10 OF 79 REFERENCES
Sexual Dimorphism in Mammals: Avian Models and Unanswered Questions
  • K. Ralls
  • Biology
    The American Naturalist
  • 1977
TLDR
An adequate mammalian model will have to include another set of factors which oppose the evolution of polygyny by increasing the spacing or mobility of females, and explain why sexual dimorphism has evolved more frequently in large mammals than in small ones.
DISENTANGLING THE CONTRIBUTION OF SEXUAL SELECTION AND ECOLOGY TO THE EVOLUTION OF SIZE DIMORPHISM IN PINNIPEDS
TLDR
This study provides novel insights into the role of sexual selection for the coevolutionary dynamics of SSD and mating system and calls for the inclusion of ecological variables when studying sexual selection and argues for caution when assuming causality between coevolving traits.
Do extra-group fertilizations increase the potential for sexual selection in male mammals?
TLDR
It is found that EGP and social mating system can predict the potential for sexual selection in mammalian populations, but only when considered jointly and not individually.
Sexual size dimorphism in mammals
TLDR
Support for the hypothesis that male-biased dimorphism relates to sexual selection on males through male–male competition for females is found, and a parallel selection pressure on female mass is identified in that age at weaning is significantly higher in more polygynous species, even when correcting for body mass.
THE ORIGINS OF SEXUAL DIMORPHISM IN BODY SIZE IN UNGULATES
TLDR
A phylogeny of extant ungulate species, along with maximum‐likelihood statistical techniques, are used to provide a test of Jarman's hypothesis, which states that sexual size dimorphism evolved in a three‐step process.
On the Opportunity for Sexual Selection, the Bateman Gradient and the Maximum Intensity of Sexual Selection
  • Adam G. Jones
  • Biology, Psychology
    Evolution; international journal of organic evolution
  • 2009
TLDR
The meaning of Bateman's principles in the context of selection theory is considered, which provides a clearer focus on the important aspects of precopulatory sexual selection than other methods and therefore should be an important part of future studies of sexual selection.
Sexual Selection and Variance in Reproductive Success
  • M. Wade
  • Biology
    The American Naturalist
  • 1979
TLDR
The purpose of this letter is to derive a concise expression for the variance in male reproductive success in terms of the variation in reproductive success among females, and to illustrate that relative parental investment as defined by Trivers is not an adequate measure of the intensity of intrasexual selection.
Variance in male reproductive success and sexual size dimorphism in pinnipeds: testing an assumption of sexual selection theory
TLDR
The theory of evolution by sexual selection for sexual size dimorphism postulates that SSD primarily reflects the adaptation of males and females to their different reproductive roles, and species with male-biased SSD are predicted to have greater variance in male reproductive success than those in which both sexes are similar in size.
Phylogenetic analyses of sexual selection and sexual size dimorphism in pinnipeds
TLDR
The hypothesis that sexual size dimorphism in pinnipeds is the product of an exclusively male response to sexual selection is supported.
...
1
2
3
4
5
...