Human sperm competition: ejaculate manipulation by females and a function for the female orgasm

@article{Baker1993HumanSC,
  title={Human sperm competition: ejaculate manipulation by females and a function for the female orgasm},
  author={R. Robin Baker and Mark A. Bellis},
  journal={Animal Behaviour},
  year={1993},
  volume={46},
  pages={887-909}
}
Abstract Abstract. Behavioural ecologists view monogamy as a subtle mixture of conflict and cooperation between the sexes. In part, conflict and cooperation is cryptic, taking place within the female's reproductive tract. In this paper the cryptic interaction for humans was analysed using data from both a nationwide survey and counts of sperm inseminated into, and ejected by, females. On average, 35% of sperm were ejected by the female within 30 min of insemination. The occurrence and timing of… 
Human sperm competition: testis size, sperm production and rates of extrapair copulations
TLDR
It is found that sperm competition is an important selection pressure operating in human populations and that the within-population frequency distribution of testis size reflects a balanced polymorphism between men who specialize in sperm competition through EPCs and men who are monogamous.
The seminal coagulum favours passage of fast-moving sperm into the uterus in the black-handed spider monkey.
TLDR
Whether the seminal coagulum of the black-handed spider monkey enhances sperm fertilisation chances by improving thefemale reproductive tract conditions, and if the female reproductive tract is 'blind' to semen or behaves selectively towards ejaculates of different males is investigated.
Pavlovian conditioning alters reproductive fitness in sperm competition and sperm allocation paradigms
TLDR
It has been shown that Pavlovian conditioning provides reproductive advantage in both sexual competition and sperm allocation paradigms, independent of other factors emphasized in previous explanations, and were probably mediated by an impact on how sperm were released from sperm stores.
Copulation, Masturbation, and Infidelity
TLDR
Suggestions that men with larger testes, men of greater bilateral symmetry, and bisexual men are morphs adapted to greater involvement in sperm competition are evaluated.
Human Sperm Competition
TLDR
This chapter presents the evidence of sperm competition in humans and concludes that sperm competition has been a important selection pressure that shaped human nature.
Male infertility, female fertility and extrapair copulations
  • O. Hasson, L. Stone
  • Biology, Medicine
    Biological reviews of the Cambridge Philosophical Society
  • 2009
TLDR
A mathematical model is presented that assumes that females have no precopulatory information about male fertility, and shows that a female EPC strategy increases female reproductive success only if certain specific conditions are upheld in the nature of male infertility.
Human female orgasm and mate fluctuating asymmetry
TLDR
The proportion of a woman's copulations associated with orgasm is predicted to be associated with her partner's fluctuating asymmetry, and a questionnaire study of 86 sexually active heterosexual couples supported this prediction.
Sperm competition in humans
TLDR
The classical theory that sperm are small simply because of the difficulties of ensuring that ova do get fertilized may also explain sperm size, and both effects are likely to contribute to the stability of anisogamy.
Ultimate Causation of Aggressive and Forced Copulation in Birds: Female Resistance, the CODE Hypothesis, and Social Monogamy
TLDR
These traits suggest that the Immediate Fertilization Enhancement Hypothesis may be an inadequate ultimate explanation for forced copulation when it occurs, and the CODE hypothesis for social monogamy predicts variation in extrapair paternity from preferred mates, variation in male reproductive success, and variation among females' post-insemination resistance mechanisms as functions of variationamong females' vulnerabilities.
Spermicide by females: what should males do?
  • J. Greff, G. Parker
  • Biology, Medicine
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2000
TLDR
A series of simple models show that arms races are not necessarily supported and identify a simple mechanistic rule for sperm killing that determines whether an arms race or sperm reduction will be favoured.
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Number of sperm in human ejaculates varies in accordance with sperm competition theory
Etude des variations de la quantite de spermatozoides emis lors des ejaculations chez l'homme et sa concordance avec la theorie de competition spermatique. Cette quantite est determinee lors de
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