Bombadier beetles again: Was: Scientist ...

Joel Duff (joelduff@nls.net)
Tue, 24 Aug 1999 20:30:54 -0700

>Here is an article from the Electronic Telegraph at:
>
>http://www.telegraph.co.uk/et?ac=000113078204876&rtmo=rhQmQmFX
>&atmo=FFFFFFtX&pg=/ et/99/8/19/ecnbom19.html
>
>which reports that the Bombardier Beetle is even more well-designed than
>previously thought, using "a pulsed rocket mechanism very similar to that
>of the V-1 or doodlebug, the first operational cruise missile which the
>Germans used to bomb England in the Second World War", with "the
>ability...to track their target for example a hind leg being bitten by an
ant -
>through their normal range of motions...", and having "a pair of shield-like
>deflectors near the opening of the tip of the beetle's abdomen..." which the
>beetles "use one at a time to enhance their marksmanship."
>
>The article points out "that there is the `vexing problem' of how the
beetle,
>which inevitably drenches itself when discharging, can withstand the heat
>and irritant effect."
>
>I would be interested to see an explanation from the scientific literature
of
>how: 1) Darwinian mechanisms of random mutation and natural selection
>could build up the evident design of the Bombardier Beetle, and 2) the
>evidence that they actually did.
>
>Note: I am aware of the `hand-waving' explanation on the Talk.Origins
>website at:
>
>http://www.talkorigins.org/faqs/bombardier.html
>
>I would be interested if someone tried to defend that `Calvin and Hobbes'
>explanation in terms of 1) and 2)!
>
>Steve

I really wish instead of quotes from the Electronic Telegraph we could get
a quote from the source PNAS which has been on-line for over a week.
Futher, in the on-line version (even if you don't have a subscription) you
can easily examine the authors's other publications by searching Medline
with the link provided. I've looked into the bombadier beetle story some
and what is most fustrating, but illuminating, is the lack of information
to be found. Really, very little research has been done on these critters
and in most cases that research has been done on a single species. Futher
those that are doing the research (check Medline) have little interest in
evolution and are either biophysicists, bioengineers, or biochemists.
Evolutionary explanation is simply a passing interest and is obivously not
the forte of authors of the papers I have seen. As a result I really can't
see that anyone looking at evolutionary questions in particular is working
with this groups, all that has been done is a simple gross cladistic
analysis using morphological characters some 30 years ago. No molecular
systematic work has been done on the group or is being done as far as I can
tell (that reminds me I was going to contact a couple of the authors to see
if anyone is doing that, hey I work with plants but I wouldn't mind
branching out if someone will provide the material). From the literature
all I can see is that closely related species have similar abilities but
certainly not the same. Looking at the broader group of beetles many have
not been characterized at all with respect to this ability to spray varying
acids from there behinds. Anyway, even the little that is know makes it
apparent that not all other species have such specialized abilities but are
to some extent intermediates. On top of that there is no fossil record,
nor would we expect much of one and even if there was of the critters,
there biochemistry would be hard to investigate. Thus how can we know
about whether there were/are or arent' intermediates. As such I can hardly
see how the Bombadier beetle makes some spectacular case for ID or for any
specific evolutionary theory.

My files are still packed from my recent move but when I get them unpacked
I will list the papers that I have in my collection. I seem to recall that
there was only one significant one that examined the biochemistry accross a
variety of related taxa.

This reminds me of the point I was trying to slip by with my post on fly
ears. If we didnt' know anything about other related flies and their
intermediate morphologies and only knew of the these flies with totally
unique ear-drums then I could easily see this as a case trumpted by IDrs as
evidence/proof of the necessity of intervention. I definitely see the
bombadier beetle as being a case of way too soon to make a judgement.

Regards,
Joel