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Sperm size and sperm competition in birds
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1992In a sample of 20 species of North American passerine birds we found no relation between sperm size and mating system like that previously reported in mammals (Gomendio & Roldan (Proc. R. Soc. Lond. B 243, 181 (1991)). Instead, we found a positive correlation between sperm length and the length of female sperm storage tubules (SSTS) and a negative ...
J V, Briskie, R, Montgomerie
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, 2014 Including data on sperm competition and on sperm competition success as binary data (yes or no)
Damian K. Dowling (335618) +3 more
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2023
Abstract Sperm competition is a form of intrasexual competition in which the sperm of two or more males concurrently occupy the reproductive tract of a single female and compete to fertilize an available ovum. As a nonmonogamous species, humans have been subject to selection pressures associated with sperm competition.
Valerie G. Starratt, Todd K. Shackelford
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Abstract Sperm competition is a form of intrasexual competition in which the sperm of two or more males concurrently occupy the reproductive tract of a single female and compete to fertilize an available ovum. As a nonmonogamous species, humans have been subject to selection pressures associated with sperm competition.
Valerie G. Starratt, Todd K. Shackelford
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Human Fertility, 2004
Although Darwin identified the evolutionary significance of competition between males in the context of reproduction, it is only in the past few decades that we have begun to appreciate the importance of competition at the gametic level. Sperm competition, defined as competition between the sperm of two or more males for fertilization of the same set ...
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Although Darwin identified the evolutionary significance of competition between males in the context of reproduction, it is only in the past few decades that we have begun to appreciate the importance of competition at the gametic level. Sperm competition, defined as competition between the sperm of two or more males for fertilization of the same set ...
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Sperm competition games: sperm selection by females
Journal of Theoretical Biology, 2003We analyse a co-evolutionary sexual conflict game, in which males compete for fertilizations (sperm competition) and females operate sperm selection against unfavourable ejaculates (cryptic female choice). For simplicity, each female mates with two males per reproductive event, and the competing ejaculates are of two types, favourable (having high ...
M A, Ball, G A, Parker
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Sperm competition in the Acari
Experimental & Applied Acarology, 1999Literature on sperm competition in the Acari is reviewed and supplemented with the author's unpublished observations. As in other animals, morphology and physiology of the female reproductive tract are key factors establishing the sperm competition pattern.
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Sperm competition influences sperm size in mammals
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1991Among mammals sperm competition leads to selection for increased sperm numbers but it is not known whether it also leads to changes in sperm size. Two contrasting theoretical predictions have been made. The first hypothesis relies on the assumption that there is a trade-off between sperm numbers and sperm size and predicts that, in species confronting ...
M, Gomendio, E R, Roldan
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SPERM COMPETITION AND THE EVOLUTION OF NONFERTILIZING SPERM IN MAMMALS
Evolution, 1991Nonfertilizing sperm with special morphologies have long been known to exist in invertebrates. Until recently, abnormal sperm in mammals were considered errors in production. Now, however, Baker and Bellis (1988, 1989) have proposed that mammalian sperm, like some invertebrate sperm, are polymorphic and adapted to a variety of nonfertilizing roles in ...
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Differences in sperm competition and sperm competition avoidance in Drosophila melanogaster
Animal Behaviour, 2008When females mate multiply (polyandry), they create opportunities for competition among males for the fertilization of their eggs. Selection is expected to favour males capable of fathering more progeny under competition or males that can somehow induce females to refrain from multiply mating.
Alberto Civetta +2 more
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Sperm competition in the Drosophila female
Molecular and General Genetics MGG, 1971Modified BS translocation males were developed at 26.0° C where univalentbearing gametes are recovered with less than half the frequency than at 18.0° C. Upon eclosion the males were stored for definite time periods at either temperature before mating individually to single y free-X females.
R C, Johnsen, S, Zarrow
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