Species description versus redescription rates: Are we getting wiser about biodiversity, more frivolous, or both?

An exit talk at the National Evolutionary Synthesis Center (NESCent) on May 22, 2013. Event details at http://nescent.org/cal/calendar_detail.php?id=965

Transcript

1. Species description
   versus redescription rates
   Are we getting wiser about biodiversity, more
   frivolous, or both?
   

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3. Species description
   

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4. Species description
   1. A new species is identified.
   

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5. Species description
   1. A new species is identified.
   2. Then: formally described and named.
   

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6. Species description
   1. A new species is identified.
   2. Then: formally described and named.
   Most species have been discovered?
   

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7. How many bird species?
   Bebber et al, 2007: 99% of bird species described!
   Cumulative species count
   Year
   

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8. How many bird species?
   Bebber et al, 2007: 99% of bird species described!
   Cumulative species count
   Year
   

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9. How many bird species?
   Bebber et al, 2007: 99% of bird species described!
   Cumulative species count
   Year
   Branta hutchinsii
   Swainson &
   Richardson, 1831
   

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10. How many bird species?
    Bebber et al, 2007: 99% of bird species described!
    Cumulative species count
    Year
    Branta hutchinsii
    Swainson &
    Richardson, 1831
    

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11. Branta hutchinsii
    1831
    1800 1830 1860 1890 1920 1950 1980 2010
    

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12. Branta hutchinsii
    1831-1872
    1800 1830 1860 1890 1920 1950 1980 2010
    Branta canadensis hutchinsii
    1872
    

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13. Branta hutchinsii
    1831-1872
    1800 1830 1860 1890 1920 1950 1980 2010
    Branta canadensis hutchinsii
    1872-2004
    Branta hutchinsii
    2004-?
    

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14. How many bird species?
    Bebber et al, 2007: 99% of bird species described!
    Cumulative species count
    Year
    Branta hutchinsii
    Swainson &
    Richardson, 1831
    

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15. How many bird species?
    Bebber et al, 2007: 99% of bird species described!
    Cumulative species count
    Year
    Branta hutchinsii
    Swainson &
    Richardson, 1831
    

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16. T
    axonomic effort
    Species description
    

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17. T
    axonomic effort
    Species description
    Species redescription
    

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18. T
    axonomic effort
    Species description
    Species redescription
    Split: one species to two or more
    

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19. T
    axonomic effort
    Species description
    Species redescription
    Split: one species to two or more
    Lump: two or more species to one
    

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20. Branta hutchinsii
    1831-1872
    1800 1830 1860 1890 1920 1950 1980 2010
    Branta canadensis hutchinsii
    1872-2004
    Branta hutchinsii
    2004-?
    Lump
    Description Split
    

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21. Back to the question
    “Are we getting wiser about biodiversity,
    more frivolous, or both?”
    Wiser: fewer lumps and splits over time
    as taxonomic understanding stabilizes.
    More frivolous: a stable number of
    lumps and splits over time.
    

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22. AOU Checklist
    A list of species found
    in a particular region.
    Continually
    updated.
    Comprehensive for
    that region.
    

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23. AOU North American Checklist
    First published in 1886.
    7 editions + 53
    incremental updates
    (supplements)
    = 60 checklists
    Every 2.1 years!
    

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24. A lot of work
    5,271 changes, additions and deletions:
    Splits/lumps: 924 changes (17%)
    

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26. Question
    Hypothesis: Are species description
    rates alone a good approximation for
    our knowledge of species diversity?
    

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27. AOU Checklist
    1998: recognized 2,008 species.
    2012: recognized 2,083 species.
    75 species “discovered” in 14 years!
    

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28. Not new descriptions!
    Centrocercus minimus J. R. Young et al, 2000
    Vermivora cyanoptera Olson & Reveal, 2009
    Actually a nomenclatural change!
    Puffinus bryani Pyle, Welch & Fleischer, 2011
    

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29. Some new introductions
    45 introduced species.
    4 deleted species.
    2 newly described species.
    T
    otal: 43 explained out of 75 (57.3%)
    And the remaining 32 species? (42.7%)
    

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30. Splits and lumps
    Splits: 34 species split from others.
    Lumps: 2 species lumped into others.
    Reinterpretation of species boundaries lead
    to +32 species:
    43% of net species change, or
    16x description rate!
    

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31. Redescriptions
    0
    10
    20
    30
    40
    1886 1895 1904 1913 1922 1931 1940 1949 1958 1967 1976 1985 1994 2003 2012
    

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32. Net change Redescriptions
    -20
    -15
    -10
    -5
    0
    5
    10
    15
    20
    1886 1895 1904 1913 1922 1931 1940 1949 1958 1967 1976 1985 1994 2003 2012
    

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33. -3.75
    0
    3.75
    7.5
    11.25
    15
    2000 2002 2004 2006 2008 2010 2012
    Splits and lumps between 2000 and 2012
    Splits: +34, Lumps: -2
    Net change: +32 species
    

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34. Splits: +6, Lumps: -9
    Net change: -3 species
    -3.75
    0
    3.75
    7.5
    11.25
    15
    1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
    Splits and lumps between 1945 and 1956
    

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35. Manual process
    Change: split
    From: Branta canadensis
    T
    o: Branta canadensis, Branta
    hutchinsii
    Citation: Checklist of North
    American birds, 45th
    supplement (2004)
    Reasons: genetics,
    morphology, ecology,
    vocal, nesting habits
    

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36. Reason
    1945-1956 (12 supplements)
    1945-1956 (12 supplements)
    1945-1956 (12 supplements) 2000-2012 (12 supplements)
    2000-2012 (12 supplements)
    2000-2012 (12 supplements)
    Reason Total: 15 Splits: 6 Lumps: 9 Total: 62 Splits: 58 Lumps: 4
    Reason
    Number Number Number Number Number Number
    No citation given 2 1 1 0 0 0
    Not available online 8 (53%) 2 6 1 1 0
    No reason given in citation 2 2 0 0 0 0
    Morphological 4 3 1 43 (69%) 42 (72%) 1
    Vocal 0 0 0 36 (58%) 34 (59%) 2
    Genetic 0 0 0 30 (48%) 28 (48%) 2
    Hybrid zones 3 2 1 14 11 3 (75%)
    Behavioral 0 0 0 12 12 0
    Ecological 0 0 0 8 8 0
    Others 1 1 0 7 6 1
    

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37. Reason
    1945-1956 (12 supplements)
    1945-1956 (12 supplements)
    1945-1956 (12 supplements) 2000-2012 (12 supplements)
    2000-2012 (12 supplements)
    2000-2012 (12 supplements)
    Reason Total: 15 Splits: 6 Lumps: 9 Total: 62 Splits: 58 Lumps: 4
    Reason
    Number Number Number Number Number Number
    No citation given 2 1 1 0 0 0
    Not available online 8 (53%) 2 6 1 1 0
    No reason given in citation 2 2 0 0 0 0
    Morphological 4 3 1 43 (69%) 42 (72%) 1
    Vocal 0 0 0 36 (58%) 34 (59%) 2
    Genetic 0 0 0 30 (48%) 28 (48%) 2
    Hybrid zones 3 2 1 14 11 3 (75%)
    Behavioral 0 0 0 12 12 0
    Ecological 0 0 0 8 8 0
    Others 1 1 0 7 6 1
    

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38. This project’s future
    Finish measuring splits and lumps and
    validating Avibase’s data collection for
    the entire AOU series (1886 to 2012).
    77 splits/lumps processed.
    278 to go.
    

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39. Future directions
    Rate of splitting/lumping might depend on:
    Improved techniques, equipment and
    species definitions, leading to better criteria.
    The authors testing, validating and
    overturning taxonomic hypotheses.
    The time taken for new hypotheses to be
    recognized and accepted.
    

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40. Sharing is caring
    Change: split
    From: Branta canadensis
    T
    o: Branta canadensis, Branta
    hutchinsii
    Citation: Checklist of North
    American birds, 45th
    supplement (2004)
    Reasons: genetics,
    morphology, ecology,
    vocal, nesting habits
    

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42. Are we getting wiser about
    biodiversity, more frivolous,
    or both?
    

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43. Images
    Wikipedia
    http://en.wikipedia.org/wiki/File:Small_Cackling_Goose_Brood.jpg
    The Wikimedia Commons:
    http://commons.wikimedia.org/wiki/File:Canada_Geese_at_Marymoor_Park.jpg
    Flickr:
    http://www.flickr.com/photos/mikebaird/2336550258/in/photostream/
    Screenshots:
    http://avibase.bsc-eoc.org
    http://sysbio.oxfordjournals.org/content/early/2013/04/10/sysbio.syt024.abstract
    http://zoobank.org
    Logos:
    http://wetlandscenter.fhsu.edu/biodiversity-on-the-web-cheyenne-bottoms-on-
    inaturalist-org/inaturalist-logo-full/
    Cover of Checklist of North American birds from: http://www.aou.org/checklist/north/print.php
    Bebber et al, 2007: http://rspb.royalsocietypublishing.org/content/274/1618/1651/
    F1.expansion.html
    

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44. References
    Bebber, D. P., Marriott, F. H. C., Gaston, K. J., Harris, S. A., and
    Scotland, R. W. 2007. Predicting unknown species numbers
    using discovery curves. Proceedings of the Royal Society B:
    Biological Sciences 274:1651-1658.
    Costello, M. J., May, R. M., and Stork, N. E. 2013a. Can we name
    earth's species before they go extinct? Science 339:413-416.
    Costello, M. J., Wilson, S., and Houlding, B. 2013b. More
    taxonomists describing significantly fewer species per unit
    effort may indicate that most species have been discovered.
    Systematic Biology.
    Coues, E. 1872. Key to North American birds. doi:10.5962/
    bhl.title.38863
    

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45. Question time!
    Thank you!
    

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