Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • News & Views
  • Published:

Evolutionary biology

Genitally does it

Nature volume 393, pages 734–735 (1998)Cite this article

The genitals of male insects bear a huge number of intricate bits and pieces. The genitalic terms for orthopterans alone (crickets and allies) include phalli, epiprocts, paraprocts, cerci, gonotremes and even titillators (from the Latin titallo, ‘tickle’).

But why have the male's genitals evolved to be so complex? Two answers have been proposed. First, the species-diagnostic nature of these male characteristics suggests that species differences in genitals may have evolved as barriers to insemination, preventing the production of low-quality hybrid offspring. So, in zones of species overlap, the female genital ‘locks’ of each species diverged, imposing Darwinian selection among conspecific males for a proper fit of each genital ‘key’. The second answer is that genital structures diverged through the sexual selection that occurs after insemination for any device that increases fertilization success. Possible examples are claspers, which hold the struggling female until insemination occurs1, or titillating devices that deliver ‘internal courtship signals’ to the female. Sperm from males with the best signals are used in preference to stored sperm from the females' previous mates, and such copulatory discrimination is favoured in females because they pass on the advantageous genital trait to their sons2.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Dorsal views of the ‘Swiss army knife’ gadgetry in the genitals of a male oriental cockroach, Blatta orientalis.

References

  1. Darwin, C. The Descent of Man and Selection in Relation to Sex 2nd edn (John Murray, London, 1874).

  2. Eberhard, W. G. Sexual Selection and Animal Genitalia (Harvard Univ. Press, Cambridge, MA, 1985).

  3. Arnqvist, G. Nature 393, 784–786 (1998).

    Article  ADS  CAS  Google Scholar 

  4. Proctor, H. C., Baker, R. L. & Gwynne, D. T. Can. J. Zool. 73, 2010–2020 (1995).

    Google Scholar 

  5. Ridley, M. Biol. Rev. 63, 509–549 (1988).

    Google Scholar 

  6. Ridley, M. Anim. Behav. 37, 535–545 (1989).

    Google Scholar 

  7. Albuquerque, G. S., Tauber, C. A. & Tauber, M. J. Evolution 50, 1598–1606 (1996).

    Google Scholar 

  8. Price, C. S. C. Nature 388, 663–666 (1997).

    Article  ADS  CAS  Google Scholar 

  9. Howard, D. J. & Gregory, P. G. Phil. Trans. R. Soc. Lond. B 340, 231–236 (1993).

    Google Scholar 

  10. Eberhard, W. G. Am. Nat. 142, 564–571 (1993).

    Google Scholar 

  11. Hunter, J. Observations on Certain Parts of the Animal Oeconomy(London, 1786).

  12. How to Know the Grasshoppers, Crickets, Cockroaches and Their Allies (Dover, New York, 1987).

  13. The Male Genitalia of Orthopteroid Insects Smithsonian Misc. Collections 96, 1-107 (1937).

Download references

Author information

Authors and Affiliations

  1. The Department of Zoology, University of Toronto in Mississauga, Mississauga, L5L 1C6, Ontario, Canada

    Darryl T. Gwynne

Authors
  1. Darryl T. Gwynne
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gwynne, D. Genitally does it. Nature 393, 734–735 (1998). https://doi.org/10.1038/31587

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1038/31587

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing