How the sperm lost its tail: the evolution of aflagellate sperm

@article{Morrow2004HowTS,
  title={How the sperm lost its tail: the evolution of aflagellate sperm},
  author={Edward H. Morrow},
  journal={Biological Reviews},
  year={2004},
  volume={79}
}
  • E. H. Morrow
  • Published 1 November 2004
  • Biology, Medicine
  • Biological Reviews
The typical sperm is comprised of a head, midpiece and flagellum. Around this theme there is an enormous diversity of form ‐ giant sperm, multi‐flagellate sperm and also sperm that lack flagella entirely. Explaining this diversity in sperm morphology is a challenging question that evolutionary biologists have only recently engaged in. Nonetheless, one of the selective forces identified as being an important factor in the evolution of sperm form is sperm competition, which occurs when the sperm… 
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References

SHOWING 1-10 OF 273 REFERENCES
SPERM COMPETITION AND THE EVOLUTION OF NONFERTILIZING SPERM IN MAMMALS
  • A. Harcourt
  • Biology, Medicine
    Evolution; international journal of organic evolution
  • 1991
TLDR
It is argued that most, maybe all, mammals are unlikely to produce nonfertilizing sperm and that sperm competition in mammals occurs through scramble competition, not contest competition.
Evolution of sperm size in nematodes: sperm competition favours larger sperm
TLDR
It was found that sperm size differed significantly with reproductive mode: males of gonochoristic species had significantly larger sperm than did males of the hermaphroditic species.
The evolution of sperm length in moths
  • E. H. Morrow, M. Gage
  • Biology, Medicine
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2000
TLDR
a comparative study examining how sperm lengths are associated with male and female reproductive characters across moths found a positive relationship between the residual testis volume and spermathecal volume, suggesting coevolution between male investment in sperMatogenesis and the extent of the female sperm storage capacity.
Sexual selection and insect sperm.
TLDR
These hypotheses have 2 difficulties explaining the full range of insect sperm-to-egg ratios: i) Even in insects whose females mate only once, males transfer excess sperm, and ii) Neither specifies an advantage to females who accept excessive numbers of sperm.
The giant sperm of a minute beetle.
TLDR
The mature sperm of Ptinella aptera is a helically coiled, flagellate gamete that move actively in the female reproductive tract and the functional significance of this behaviour and of the evolution of the large gamete itself is discussed in relation to existing hypotheses.
Mating system evolution in sperm-heteromorphic Drosophila.
TLDR
Different responses between sperm-heteromorphic and sperm-monomorphic systems underscore the complex nature of the coevolution between male and female mating system characters.
THE EVOLUTION OF SPERM SIZE IN BIRDS
TLDR
It is suggested that future models of sperm‐size evolution consider not only the role of sperm competition, but also how female control and manipulation of ejaculates after insemination selects for different sperm morphologies.
Sperm Competition in Fishes: The Evolution of Testis Size and Ejaculate Characteristics
TLDR
It is found that both the gonadosomatic index and sperm numbers increase with intensity of sperm competition across species but that sperm length decreases, which does not fit predictions of current sperm competition theory.
Only long sperm are fertilization-competent in six sperm-heteromorphic Drosophila species
TLDR
Fertilization in six obscura group species was examined using anti-sperm antibodies and digital deconvolution microscopy and it was found that all eggs were fertilized by only the long sperm type, even in polyspermic eggs.
Experimental Evidence for the Evolution of Numerous, Tiny Sperm via Sperm Competition
TLDR
Paternity success across 77 two-male sperm competitions shows that males producing both relatively small sperm and relatively numerous sperm win competitions for fertilization, providing direct experimental support for the theory that sperm competition selects for maximal numbers of miniaturized sperm.
...
1
2
3
4
5
...