Global priorities for conserving the evolutionary history of sharks, rays and chimaeras

  • Nature Ecology & Evolutionvolume 2pages288298 (2018)
  • doi:10.1038/s41559-017-0448-4
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In an era of accelerated biodiversity loss and limited conservation resources, systematic prioritization of species and places is essential. In terrestrial vertebrates, evolutionary distinctness has been used to identify species and locations that embody the greatest share of evolutionary history. We estimate evolutionary distinctness for a large marine vertebrate radiation on a dated taxon-complete tree for all 1,192 chondrichthyan fishes (sharks, rays and chimaeras) by augmenting a new 610-species molecular phylogeny using taxonomic constraints. Chondrichthyans are by far the most evolutionarily distinct of all major radiations of jawed vertebrates—the average species embodies 26 million years of unique evolutionary history. With this metric, we identify 21 countries with the highest richness, endemism and evolutionary distinctness of threatened species as targets for conservation prioritization. On average, threatened chondrichthyans are more evolutionarily distinct—further motivating improved conservation, fisheries management and trade regulation to avoid significant pruning of the chondrichthyan tree of life.

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We are grateful to A. J. Aberer for useful discussion of rogue taxon exclusion, D. Ebert and W. White for taxonomic guidance, G. J. P. Naylor, X. Vélez-Zauzo, A. Godknecht, M. Gollock, H. Koldewey and M. D’Angelo for research support, and B. Corrie and M. Siegert for computing access. We thank all IUCN Shark Specialist Group members and all additional experts who have contributed data and their expertise to IUCN Red List assessments. This work was carried out at the Interdisciplinary Research in Mathematics and Computer Sciences Centre, Simon Fraser University (, the Swiss Shark Foundation computing cluster and Compute Canada’s Westgrid computing network. This study was funded by Save Our Seas Foundation, Rufford Foundation, Zoological Society London, Natural Science and Engineering Research Council Discovery and Accelerator Awards, and Canada Research Chairs Program. Shark and ray silhouettes in Figs. 1, 2 and 4 were created by C.G.M from images by R. Aidan Martin; all silhouettes in Fig. 3 were created by M. Dando.

Author information

Author notes

  1. R. William Stein and Christopher G. Mull contributed equally to this work.


  1. Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada

    • R. William Stein
    • , Christopher G. Mull
    • , Lindsay N. K. Davidson
    • , Gordon J. Smith
    • , Nicholas K. Dulvy
    •  & Arne O. Mooers
  2. Scimitar Scientific, Whitehorse, Yukon, Canada

    • Tyler S. Kuhn
  3. Biology Department, St Ambrose University, Davenport, IA, USA

    • Neil C. Aschliman
  4. BC Centre for Excellence in HIV/AIDS, University of British Columbia, Vancouver, British Columbia, Canada

    • Jeffrey B. Joy
  5. Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada

    • Jeffrey B. Joy


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N.K.D. and A.O.M. conceived and led the project, R.W.S., C.G.M., J.B.J., T.S.K., N.C.A., L.N.K.D. and A.O.M. designed the project. N.C.A., R.W.S., C.G.M., J.B.J., G.J.S. and L.N.K.D. acquired or provided data. R.W.S., T.S.K., J.B.J. and L.N.K.D. contributed essential code and analyses. R.W.S., C.G.M., L.N.K.D., N.K.D. and A.O.M. drafted and revised the paper. R.W.S. designed and led the phylogenetic work, C.G.M. supported the phylogenetic work and led the subsequent statistical analyses, and L.N.K.D. led the spatial analyses.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Christopher G. Mull or Nicholas K. Dulvy or Arne O. Mooers.

Supplementary information

  1. Supplementary Information

    Supplementary results and tables

  2. Life Sciences Reporting Summary

  3. Supplementary table 1

    Master taxonomy dataset

  4. Supplementary table 2

    Accession dataset

  5. Supplementary table 3

    Fossil calibration dataset

  6. Supplementary table 4

    Mixed clade and tree modification dataset

  7. Supplementary table 5

    Vertebrate comparison dataset

  8. Supplementary table 6

    Recently described species dataset

  9. Supplementary code 1

    Species addition R script

  10. Supplementary code 2

    Polytomy resolver R script

  11. Supplementary code 3

    XML creator R script