Just in case you missed it, be sure to check out Andrew Yost's post on
a parallel thread addressing this same topic. He gives the history of term
"biodiversity" and quotes some authors with very interesting insights.
Now for my one-fiftieth of a dollar: I think it is futile and wrong
to search for one all-encompassing definition of diversity. Doing so
implies that there exists in the real world some conceptual entity that
could be mapped to the term, and that isn't necessarily so. Rather, I
suggest a pragmatic approach that selects an aspect of diversity that
relates to the problem one is discussing. If I am working on a theory or
field project that has to do with energy and nutrient flow through trophic
levels, a diversity index emphasizing biomass over other aspects may be best
(i.e., I may not care too much whether my grass is being eaten by antelopes
or grasshoppers, just how efficiently they convert it.) If I am studying
the evolution of host-race formation in butterflies, a diversity index that
emphasizes species-counts might be the best thing. Would I ever want to
integrate data of the trophic-levels project with the host-race formation
project? If not, why should I care that they do not rely on the same
measure of (or definition of) diversity?
In this vein, I should point out, as another poster in that parallel
thread did, that "diversity" is often applied to taxonomic groups rather
than ecosystems (e.g., higher phasmid diversity in Ecuador than in
Michigan). This seems pretty clear-cut, but in cases where the taxonomy is
complex (swarms of sibling species, high phenotypic plasticity,
introgressive hybridization, etc.) it may break down.
The originator of this thread is interested in diversity relative to
popular perceptions an public conservation policy, but I question whether we
should resort to a rigorous definition of diversity for these purposes.
What does it get us? Why not instead focus on habitat preservation (perhaps
keyed to charismatic megafauna), and hope that that gets done what is
needed. I submit that in most cases diversity preservation can not be
justified on scientific grounds. Rather, how we treat the environment will
be a consequence of our economic, aesthetic, and even spiritual values
weighed against the needs of a burgeoning human population. Let's argue to
preserve our habitats because they are valuable, beautiful, and sacred, not
because the score high on a diversity measure. Either way, it's a sales job
to the stake holders and decision makers, but the former is probably much
easier to sell.
Martin M. Meiss
2010/12/16 Matt Chew <[email protected]>
> This has been an interesting thread. I may have missed something, but I
> don't recall anyone mentioning David Takacs' book 'The Idea of
> Biodiversity:
> Philosophies of Paradise' (Johns Hopkins, 1996) which includes interviews
> with then-prominent (mostly still active) ecologists and conservation
> biologists and examines most of the conceptual points made here so far. As
> an inspiration or motivation, biodiversity still appeals to those who
> consider it more scientifically substantial-sounding than 'nature'.
> However, our various attempts to define it in 2010 echo those made 15 years
> ago, both in their earnestness and futility. It cannot be made
> simultaneously comprehensive and precise. If biodiversity is
> all-inclusive,
> it is useless in scientific practice, and we must conceptually pull it to
> bits to work with it. In 1996 Takacs paid relatively less attention to the
> second part of the original question here: "Does the term capture the
> public's attention?" Well, how can we know? Using the popular but
> admittedly fraught 'Googling' method, a Google News search done just now
> returned 2,625 hits for 'biodiversity' but 60,249 for 'nature'. As a term,
> biodiversity, like "free market", sounds appealing. The devil is in the
> details.
>
> Matthew K Chew
> Assistant Research Professor
> Arizona State University School of Life Sciences
>
> ASU Center for Biology & Society
> PO Box 873301
> Tempe, AZ 85287-3301 USA
> Tel 480.965.8422
> Fax 480.965.8330
> [email protected] or [email protected]
> http://cbs.asu.edu/people/profiles/chew.php
> http://asu.academia.edu/MattChew
>
