Skip to main content

Thank you for visiting 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.

  • Letter
  • Published:

Nonconstant extinction rates of Neogene planktonic foraminifera


Van Valen's ‘new evolutionary law’1 has provoked considerable discussion of survivorship of fossil taxa2–5 and of the Red Queen's hypothesis6–7. Van Valen's principal conclusion was that survivorship curves of fossil taxa are essentially linear1, indicating that the mean probability of extinction within an ecologically homogeneous group has been constant1,8. Despite some criticism about his methodology9–11, constant extinction rates have been regarded as the general rule for fossil taxa12 and the empirical basis for the Red Queen's hypothesis7,13,14. We show here the fallacy of the concept of constant extinction rates by applying his survivorship-curve technique1,2 to longevity data for Neogene planktonic foraminifera15 which clearly exhibit nonconstant extinction rates through geological time. The linearity of survivorship curves only indicates that the probability of extinction of a species is independent of its longevity. The mean longevities and extinction rates of tropical, transitional and temperate assemblages are statistically similar.

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

Access options

Buy this article

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

Similar content being viewed by others


  1. Van Valen, L. Evol. Theory 1, 1–30 (1973).

    Google Scholar 

  2. Raup, D. M. Paleobiology 1, 82–96 (1975).

    Article  Google Scholar 

  3. Hallam, A. Nature 259, 12–13 (1976).

    Article  ADS  Google Scholar 

  4. Van Valen, L. Nature 260, 575 (1976).

    Article  ADS  Google Scholar 

  5. McCune, A. R. Evolution 36, 610–614 (1982).

    Article  Google Scholar 

  6. Maynard Smith, J. Am. Nat. 110, 325–330 (1976).

    Article  Google Scholar 

  7. Stenseth, N. C. Oikos 33, 196–227 (1979).

    Article  Google Scholar 

  8. Van Valen, L. Evol. Theory 4, 129–142 (1979).

    Google Scholar 

  9. Foin, T. C., Valentine, J. W. & Ayala, F. J. Nature 257, 514–516 (1975).

    Article  ADS  CAS  Google Scholar 

  10. Sepkoski, J. J. Jr Paleobiology 1, 343–355 (1975).

    Article  Google Scholar 

  11. Salthe, S. H. Paleobiology 1, 356–358 (1975).

    Article  Google Scholar 

  12. Schopf, T. J. M. Paleobiology 5, 337–352 (1979).

    Article  Google Scholar 

  13. Lewontin, R. C. Scient. Am. 239, 212–231 (1978).

    Article  CAS  Google Scholar 

  14. Arnold, J. A. Proc. 3rd N. Am. Paleont. Convention 1, 9–12 (1982).

    Google Scholar 

  15. Kennett, J. P. & Srinivasan, M. S. Neogene Planktonic Foraminifera: A Phylogenetic Atlas (Hutchinson & Ross, Pennsylvania, 1983).

    Google Scholar 

  16. Wei, K.-Y. & Kennett, J. P. Paleobiology (in the press).

  17. Stehli, F. G., Douglas, R. G. & Kafescioglu, I. A. in Models in Paleobiology (ed. Schopf, T. J. M.) 116–128 (Freeman, San Francisco, 1972).

    Google Scholar 

  18. Blow, W. H. in Proc. 1st Int. Conf. Plank. Microfossils, Geneva 1, 199–422 (1969).

    Google Scholar 

  19. Srinivasan, S. M. & Kennett, J. P. Mar. Micropaleont. 6, 499–533 (1981).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

About this article

Cite this article

Wei, KY., Kennett, J. Nonconstant extinction rates of Neogene planktonic foraminifera. Nature 305, 218–220 (1983).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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.


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