Endangered Genera (or Families)?
Shueyi at AOL.COM
Fri Jan 8 09:48:40 CST 1999
This is actually a pretty interesting philosophical question, and unlike John
Grehan, I have some opinions that I'll share. My response is drawn from the
perspective of a conservation practitioner, who trained in both ecology and
< Are there any lists (governmental or otherwise) that concentrate on
<"endangered" high taxa like genera and families. Given that extinctions
<are unfortunately a part of modern life, I wonder if anyone tries any
<kind of taxonomic "triage", so that species of less speciose genera or
<families, might be given a bit more attention than very speciose genera
<or families. Of course there are other things to consider, but in
<general wouldn't limited resources be best spent if we tried to
<concentrate on overall genetic biodiversity.
A question arises about where real genetic biodiversty resides. Does a taxon
that represents the lone species of a highly derived lineage represnt "more"
genetic diversity than does a complex of poorly understood sibling species
that pass as a single morphospecies? How about high underived taxa, which
retain many ancestral charcahters and hence are termed "primative" - why would
they be more genetically rich than "normally" evoloved entities.
A second point is the level at which extinction occurs. Extiction is a
population-level process. If extintion run unchecked, it can, does and has
consumed entire species. The question posed above seems to revolve around
extinction at the higher taxonomic category, especially as it relates to high
taxa represented by very few species. But given that exiction happens at the
population level, does targeting and conserving a genus really make sence just
because it is really different? Should not that entity actually be imperiled
before scarce conservation dollars are spent to conserve it? And if it is
imperiled, then its the species that we are interested in isn't it - not the
higher taxonomic category per say.
Third, this implies that biodiversity conservation proceeds on a species-by-
species approach. In practice, only the U.S. Fish and Wildlife Service and
the ICCUN take this approach. Most conservation organizations are targeting
ecosystems as singular target - assuming that you capture all the component
species in the process. Targeting and conserving single species, while
sometimes a necsseity, is very cost prohibitive. Where possible, organization
like the one I work for try to take a broad approach. For example, the
Conservancy just worked out a deal that added 2,000,000 acres to Noel Kempf
National Park in Bolivia (includes a diverse mosiac of savanna, wetlands, and
mountain rainforest with extensive riverine systems entirely contained within
the park). This creates a conserved area of almost 4M acres, that is likely a
viable conservation area for all resident species. Other, equally important
landscapes are being worked on throught the hemiphere. Targeting single
species will never yield such coherently designed conservation areas as these.
< A species like the "bumblebee" bat, which I assume is still
<endangered, being the sole member of a monotypic family (and of even
<greater evolutionary importance because of its place in chiropteran
<evolution), as an example. Is it given any kind of extra protection
<because it could be argued to be a more importance piece of biodiversity
<than let's say an endangered species in a speciose genus of insect,
<mollusc, or angiosperm. Perhaps this is already being done? Just
<wanted to get some feedback on this while it has popped back into my
This argument places relative "conservation value" on species. (This one is
more important than that one because...). I persoanly can't assign value to
every species on the planet, so that I can develop a prioritized list of which
to save and which to allow to become extinct. Further, I remain an optimist,
and feel that with well leveraged action, that we can indeed stabalize the
current biodiversity crisis facing the World.
Towards that end, current planning efforts for conservation are designed to
conserve representative viable examples of all community types, using the
appropriate level of geographic redundancy for each community type, such that
the vast majority of indiviual species captured within a suite of conserved
sites. Such as system should capture genitic diversty across species ranges,
as well as get all or most of those entities that we've been discussing on the
"morphospecies" thread. Of course, some species are so rare that they will be
missed by this community approach, and these species do have to be targeted
individually. But they are targeted only after the more"cost effective"
NOW that I've said all of that, there is one higher taxonomic group that I am
very concerned about - Unionid Mussels. Around 60% of the US species are
either extinct or critically imperiled. In the Midwestern US, we are spending
an inordinate amount of time trying to figure out where and how to save these
amazing animals. And because they are so rare, we usually approach
conservation of mussels species by species. It's a pain in the ass, and
amazingly expensive (in Indiana, a small state, we spent almost over $500,000
last year on watershed projects, and we will likely double that amount three
years from now. All for about 100 mussels. .
Some cladistic analyses have been applied to ranking taxa
with different weghts according to their position on the
cladogram (some British Museum people). There have
been some papers published on this,
but I don't have the most recent (perhaps someone on this
list knows them).
A couple of the older ones are:
Vane-Wright et al. (1991) What to protect? - systematics and the
agony of choice. Biological Conservation 55, 235-254.
Williams, P. H. et al. (1991) Measuring biodiversity: taxonomic
relatedness for conservation priorities. Australian Systematic Botany 4,
I have no personal judgement on their validity, but no doubt views
on this will be as complex as cladistic analysis gets in general.
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