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.

Sex releases the speed limit on evolution

Abstract

Explaining the evolutionary maintenance of sex remains a key problem in evolutionary biology1,2,3. One potential benefit of sex is that it may allow a more rapid adaptive response when environmental conditions change, by increasing the efficiency with which selection can fix beneficial mutations4,5,6,7. Here I show that sex can increase the rate of adaptation in the facultatively sexual single-celled chlorophyte Chlamydomonas reinhardtii, but that the benefits of sex depend crucially on the size of the population that is adapting: sex has a marked effect in large populations but little effect in small populations. Several mechanisms have been proposed to explain the benefits of sex in a novel environment, including stochastic effects in small populations, clonal interference and epistasis between beneficial alleles. These results indicate that clonal interference is important in this system.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Effect of bottleneck size on adaptation in asexual populations.
Figure 2: Interaction between sex and bottleneck size.

Similar content being viewed by others

References

  1. Maynard Smith, J. The Evolution of Sex (Cambridge Univ. Press, Cambridge, 1978)

    Google Scholar 

  2. Bell, G. The Masterpiece of Nature (Croom Helm, London, 1982)

    Google Scholar 

  3. West, S. A., Lively, C. M. & Read, A. F. A pluralist approach to sex and recombination. J. Evol. Biol. 12, 1003–1012 (1999)

    Article  Google Scholar 

  4. Fisher, R. A. The Genetical Theory of Natural Selection (Clarendon, Oxford, 1958)

    MATH  Google Scholar 

  5. Muller, H. J. Some genetic aspects of sex. Am. Nat. 66, 118–138 (1932)

    Article  Google Scholar 

  6. Otto, S. P. & Barton, N. H. The evolution of recombination: removing the limits to natural selection. Genetics 147, 879–906 (1997)

    CAS  PubMed  PubMed Central  Google Scholar 

  7. Burt, A. Perspective: Sex, recombination, and the efficacy of selection—was Weismann right? Evolution 54, 337–351 (2000)

    CAS  PubMed  Google Scholar 

  8. Gerrish, P. J. & Lenski, R. E. The fate of competing mutations in an asexual population. Genetica 102/103, 127–144 (1998)

    Article  Google Scholar 

  9. de Visser, J. A. G. M., Zeyl, C. W., Gerrish, P. J., Blanchard, J. L. & Lenski, R. E. Diminishing returns from mutation supply rates in asexual populations. Science 283, 404–406 (1999)

    Article  ADS  CAS  Google Scholar 

  10. Miralles, R., Gerrish, P. J., Moya, A. & Elena, S. F. Clonal interference and the evolution of RNA viruses. Science 285, 1745–1747 (1999)

    Article  CAS  Google Scholar 

  11. Otto, S. P. & Barton, N. H. Selection for recombination in small populations. Evolution 55, 1921–1931 (2001)

    Article  CAS  Google Scholar 

  12. Colegrave, N., Kaltz, O. & Bell, G. The ecology and genetics of fitness in Chlamydomonas. VIII. The dynamics of adaptation to novel environments after a single episode of sex. Evolution 56, 14–21 (2002)

    Article  Google Scholar 

  13. Vasi, F., Travisano, M. & Lenski, R. E. Long-term experimental evolution in Escherichia coli. 2. Changes in life-history traits during adaptation to a seasonal environment. Am. Nat. 144, 432–456 (1994)

    Article  Google Scholar 

  14. Goho, S. & Bell, G. Mild environmental stress elicits mutations affecting fitness in Chlamydomonas. Proc. R. Soc. Lond. B 267, 123–129 (2000)

    Article  CAS  Google Scholar 

  15. Lenski, R. E., Rose, M. R., Simpson, S. C. & Tadler, S. C. Long-term experimental evolution in Escherichia coli. I. Adaptation and divergence during 2,000 generations. Am. Nat. 138, 1315–1341 (1991)

    Article  Google Scholar 

Download references

Acknowledgements

I thank N. Barton, G. Bell, T. Johnson and S. Nee for discussion of this experiment and for comments on the manuscript; A. Poon for suggestions for improvement to earlier versions; S. Otto and A. Read for advice at early stages; and D. Haydon, L. Kruuk and M. Spencer for lengthy discussions on curve fitting. This work was supported by a NERC postdoctoral fellowship.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Nick Colegrave.

Ethics declarations

Competing interests

The author declares that he has no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Colegrave, N. Sex releases the speed limit on evolution. Nature 420, 664–666 (2002). https://doi.org/10.1038/nature01191

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature01191

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

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