Sex-Ratio Variation in Response to Interspecific Competition

@article{Dickman1988SexRatioVI,
  title={Sex-Ratio Variation in Response to Interspecific Competition},
  author={Chris R. Dickman},
  journal={The American Naturalist},
  year={1988},
  volume={132},
  pages={289 - 297}
}
  • C. Dickman
  • Published 1 August 1988
  • Biology
  • The American Naturalist
An important yet controversial hypothesis n evolutionary biology is that natural selection may sometimes favor parental control of the sex of offspring. Fisher (1930) initially proposed that sexually reproducing organisms hould, over their lifetimes, invest equally in sons and daughters and hence that the equilibrium sex ratio of newly independent young should be 1: 1. He also pointed out that if members of one sex were overproduced, stabilizing selection would return the population sex ratio… 
Male-biased sex ratios in New Zealand fur seal pups relative to environmental variation
TLDR
It is suggested that some plasticity in the determination of pup sex among years is a mechanism by which A. forsteri females in New Zealand, and perhaps other otariid seals, can maximise fitness benefits when living in regions of high, yet apparently predictable, environmental variability.
Costs of Rearing the Wrong Sex: Cross-Fostering to Manipulate Offspring Sex in Tammar Wallabies
TLDR
A cross-fostering experiment in free-ranging tammar wallabies found some support for both hypotheses in that rearing an unexpected son or an unexpected daughter both lead to reduced future maternal fitness, and suggests that there may be context-specific costs associated with rearing the “wrong” sex.
Emerging sex allocation research in mammals: marsupials and the pouch advantage
TLDR
This review highlights the apparent frequency, in marsupial mammals, of sex ratio bias, which has largely been recorded as conforming to one of a few hypotheses.
Sex‐ratio meiotic drive and interspecific competition
TLDR
It is shown that, with strong competition, sex‐ratio meiotic drive systems can result in a significant shift in community composition because the effective birth rate in the population may be increased by a female‐biased sex ratio.
Adaptive sex allocation by brood reduction in antechinuses
  • A. Cockburn
  • Biology
    Behavioral Ecology and Sociobiology
  • 2004
TLDR
Observations in Antechinuses suggest that in populations where females are largely semelparous, the population optimum generated by local resource competition may be unattainable, because of the importance of producing at least one daughter.
Size breeds success: multiple paternity, multivariate selection and male semelparity in a small marsupial, Antechinus stuartii
TLDR
Investigation of selection in male brown antechinus, Antechinus stuartii, and paternity success in 119 males is found to be related most strongly to body mass and scrotal size, thus providing support for both hypotheses for the evolution of semelparity.
Birth sex ratios in toque macaques and other mammals: integrating the effects of maternal condition and competition
  • W. Dittus
  • Biology
    Behavioral Ecology and Sociobiology
  • 1998
TLDR
New predictions integrate effects, proposed by Trivers and Willard, that are rooted in male mate competition, with those of local resource competition (and/or female reproductive competition), which are not universal and differ in intensity between the socioecologies and local environments of different species.
Variation in Sex Ratios of Offspring in Wild Bushy-Tailed Woodrats
TLDR
Analysis of litters of wild bushy-tailed woodrats suggests that yearlings may adjust sex ratios during the investment period from birth to weaning, and postbirth loss was more strongly male-biased in litters born to yearling mothers than in those born to adults.
Generation of sex ratio biases in the red-tailed phascogale (Phascogale calura).
TLDR
The sex ratio of embryos and pouch young, and the degree of embryonic overproduction, in red-tailed phascogales (Phascogale calura) was investigated to gain an understanding of the mechanism by which sex biases may be generated.
...
...

References

SHOWING 1-10 OF 23 REFERENCES
Dominance Rank, Secondary Sex Ratio, and Reproduction of Offspring in Polygynous Primates
TLDR
A model proposed by Trivers and Willard (1973), however, specified how deviations from equal PI may be favored by natural selection according to the influence of maternal condition on the reproduction of offspring.
The question of adaptive sex ratio in outcrossed vertebrates
  • G. Williams
  • Biology
    Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1979
TLDR
Of various published theories of adaptive control of progeny sex ratio only two are plausible, a physiological theory by Trivers & Willard, and a demographic theory by Verner, which postulates a minimization of competition for mates in neighbourhoods subject to random fluctuation in sex ratio.
Sex-ratio manipulation in the common opossum
TLDR
The female common opossum (Didelphis marsupialis), whose capacity for parental investment was artificially enhanced by dietary supplementation, produces male-biased sex ratios, in contrast to the unbiased ratios produced by control females.
Sex Ratio Variation in Mammals
TLDR
Valid evidence that sex ratio trends are adaptive must be based on the overall distribution of trends or on cases in which the sex ratio can be shown to vary with the relative fitness of producing sons and daughters.
Selective Abortion of Entire Litters in the Coypu: Adaptive Control of Offspring Production in Relation to Quality and Sex
TLDR
Data from a 12-yr study of coypu reproductive biology suggest that adaptive control may exist in this species and that one mechanism is the selective abortion of entire litters.
Natural Selection of Parental Ability to Vary the Sex Ratio of Offspring
Theory and data suggest that a male in good condition at the end of the period of parental investment is expected to outreproduce a sister in similar condition, while she is expected to outreproduce
Social dominance and habitat utilization in Antechinus stuartii (Marsupialia)
TLDR
The life history of this species appears to be geared to predictable seasonal food resources, but it may not be optimal throughout the present range, and the species seems to be evolutionarily trapped.
Niche compression: Two tests of an hypothesis using narrowly sympatric predator species
TLDR
Two tests of the predicted resource shifts using narrowly sympatric species of predatory marsupials are described, and three situations in which the predictions of the compression hypothesis may generally not apply are suggested.
Experimental Manipulation of Population Density in Three Sympatric Rodents
TLDR
Three abundant rodents, the cotton rat (Sigmodon hispidus), the harvest mouse (Reithrodontomys fulvescens), and the rice rat (Oryzomys palustris) are sympatric in southeast Texas, and a significant change in sex ratio of cotton rats was recorded in the areas where harvest mice and rice rats were removed.
An ecological study of Antechinus stuartii (Marsupialia) in a south-east Queensland rain forest
  • D. Wood
  • Environmental Science, Biology
  • 1970
TLDR
Mortality had a greater influence on population size than reproduction, and late sexual maturity and stereotyped reproductive pattern seem to preclude cyclical changes in population density.
...
...