Sunday, July 20, 2008

Species-Scape

 
This is a snapshot of an animated picture of a "species-scape." The size of the organisms represent their relative abundance on Earth. See Species-Scape on the Cornell University website.

Another version is shown on Christopher Taylor's blog Catalogue of Organisms [The Species-Scape Picture].

Notice how insignificant mammals are, yet one particular species of mammal has the potential to ruin the entire planet for all other species.

Some groups seem to be missing, bryophytes (moss) for example. Can you find any others?


8 comments :

  1. How can we be "insignificant" and have the potential to ruin the planet?

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  2. The systematics seems to be very naive. Bacteria are called 'Monera', and there's no mention of Archaea at all! All 'Algae' are lumped together, as are all 'Protozoa'.

    Also, I would have expected 'abundance' to mean number of individuals, not number of species.

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  3. Notice how insignificant mammals are, yet one particular species of mammal has the potential to ruin the entire planet for all other species.


    That strikes me as another odd comparison along with abundance; would it be any less surprising if we would have been a beetle species?

    The picture is a nice example of framing, though. :-P

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  4. Methinks 'Monera' is WAY underrepresented at 5000 species.

    For example, Gans et al. (2005, Science 309(5739):1387-9) estimated 830,000 bacterial species per gram of soil! Curtis et al. (2002, PNAS 99(16):10494-9) made a lower estimate of 6400 - 38,000 specied per gram of soil, but still estimated that a ton of soil might contain 4 million species, with the oceans contributing another 2 million species.

    Even old papers suggest many more than 5000 total bacterial species. (E.g. Torsvik et al., 1990, Appl Environ Microbiol 56:782-7 found 4000 soil species at a single Norwegian site.)

    Based on that, the Moneran should probably occupy at least 80% of the picture!

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  5. Very interesting! What would the diagram look like if the category partitioning was different? - for example biomass per phylum or species. Would this reveal anything worthwhile?

    And what about that knotty subject of complexity? Assuming we had a robust measure of complexity would we find that phylum or species biomass drops off with complexity as Gould suggested? Does the fact that humans seem to have onboard the heuristic apparatus capable of discovering/creating further heuristics invalidate Gould's graph?

    Does the peculiarly fecund nature of human heuristic inventiveness have something to do with the potential to wreck the planet? In human beings has evolutionary history reached one of those ‘phase changes’ (compare stramatolite oxygen output) that gives rise to nonlinear instabilities?

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  6. For those interested in a diversity v. biomass comparison, the Xerces society has some nice (although less artistic) diagrams to that effect. Googling "Xerces invertebrate diversity" should turn it up.

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  7. Googling "Xerces invertebrate diversity" should turn it up.

    Thanks Neil! I managed to lock on to that!

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