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Sexual dimorphism in trait variability and its eco-evolutionary and statistical implications

  1. Susanne RK Zajitschek  Is a corresponding author
  2. Felix Zajitschek
  3. Bonduriansky Russell
  4. Robert C Brooks
  5. Will Cornwell
  6. Daniel S Falster
  7. Malgorzata Lagisz
  8. Jeremy Mason
  9. Alistair M Senior
  10. Daniel AW Noble
  11. Shinichi Nakagawa  Is a corresponding author
  1. Liverpool John Moores University, United Kingdom
  2. University of New South Wales, Australia
  3. European Bioinformatics Institute, United Kingdom
  4. University of Sydney, Australia
  5. Australian National University, Australia
Research Article
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Cite this article as: eLife 2020;9:e63170 doi: 10.7554/eLife.63170

Abstract

Biomedical and clinical sciences are experiencing a renewed interest in the fact that males and females differ in many anatomic, physiological, and behavioral traits. Sex differences in trait variability, however, are yet to receive similar recognition. In medical science, mammalian females are assumed to have higher trait variability due to estrous cycles (the 'estrus-mediated variability hypothesis'); historically in biomedical research, females have been excluded for this reason. Contrastingly, evolutionary theory and associated data support the 'greater male variability hypothesis'. Here, we test these competing hypotheses in 218 traits measured in >26,900 mice, using meta-analysis methods. Neither hypothesis could universally explain patterns in trait variability. Sex-bias in variability was trait-dependent. While greater male variability was found in morphological traits, females were much more variable in immunological traits. Sex-specific variability has eco-evolutionary ramifications including sex-dependent responses to climate change, as well as statistical implications including power analysis considering sex difference in variance.

Article and author information

Author details

  1. Susanne RK Zajitschek

    School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
    For correspondence
    susi.zajitschek@gmail.com
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4676-9950
  2. Felix Zajitschek

    BEES, University of New South Wales, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6010-6112
  3. Bonduriansky Russell

    BEES, University of New South Wales, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
  4. Robert C Brooks

    BEES, University of New South Wales, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
  5. Will Cornwell

    Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
  6. Daniel S Falster

    Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
  7. Malgorzata Lagisz

    BEES, University of New South Wales, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
  8. Jeremy Mason

    European Bioinformatics Institute, Cambridge, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  9. Alistair M Senior

    School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9805-7280
  10. Daniel AW Noble

    Research School of Biology, Australian National University, Canberra, Australia
    Competing interests
    The authors declare that no competing interests exist.
  11. Shinichi Nakagawa

    School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
    For correspondence
    s.nakagawa@unsw.edu.au
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7765-5182

Funding

Australian Research Council (DP180100818)

  • Shinichi Nakagawa

NIH Common Fund (UM1-H G006370)

  • Jeremy Mason

Australian Research Council Fellowship (DE180101520)

  • Alistair M Senior

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Rosalyn Gloag, University of Sidney, Australia

Publication history

  1. Received: September 16, 2020
  2. Accepted: October 30, 2020
  3. Accepted Manuscript published: November 17, 2020 (version 1)

Copyright

© 2020, Zajitschek et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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