Bombardier beetle 235634 221529536 2008-06-24T22:21:15Z Aunt Entropy 6417583 /* Creationism and Bomby the Bombardier Beetle */ okay, cutting; linked to previously '''Bombardier Beetles''' are [[ground beetle]]s ([[Carabidae]]) in the tribes [[Brachinini]], [[Paussini]], [[Ozaenini]], or [[Metriini]]—more than 500 [[species]] altogether—that are most notable for the defense mechanism that gives them their name: They can fire a mixture of chemicals from special [[gland]]s in their abdomen. {{Taxobox | name = Bombardier beetles | image = Brachinus spPCCA20060328-2821B.jpg | image_width = 205px | image_caption = ''Brachinus'' species | regnum = [[Animal]]ia | phylum = [[Arthropod]]a | classis = [[Insect]]a | ordo = [[beetle|Coleoptera]] | familia = [[Ground beetle|Carabidae]] | subdivision_ranks = Tribes | subdivision = '''[[Brachinini]]'''<br> '''[[Paussini]]'''<br> '''[[Ozaenini]]'''<br> '''[[Metriini]]''' }} {{wikispecies|Brachinini}} [[Image:Pheropsophus verticalis 01 Pengo.jpg|thumb|Australian Bombardier Beetle (''Pheropsophus verticalis'')]] Bombardier beetles store two separate chemicals ([[hydroquinone]] and [[hydrogen peroxide]]). When they are threatened, the two chemicals are squirted through two tubes, where they are mixed along with small amounts of catalytic enzymes and undergo a violent [[exothermic]] chemical reaction. The boiling, foul-smelling liquid partially becomes a gas ([[flash evaporation]]) and is expelled with a loud popping sound. ==Defense mechanism == Secretory cells produce hydroquinones and hydrogen peroxide (and perhaps other chemicals, depending on the species), which collect in a reservoir. The reservoir opens through a muscle-controlled valve onto a thick-walled reaction chamber. This chamber is lined with cells that secrete catalases and peroxidases. When the contents of the reservoir are forced into the reaction chamber, the catalases and peroxidases rapidly break down the hydrogen peroxide and catalyze the oxidation of the hydroquinones into p-quinones. These reactions release free oxygen and generate enough heat to bring the mixture to the boiling point and vaporize about a fifth of it. Under pressure of the released gasses, the valve is forced closed, and the chemicals are expelled explosively through openings at the tip of the abdomen. Each time it does this it shoots about 70 times very rapidly. The damage caused can be fatal to attacking insects and small creatures and is painful to human skin. ==Creationism and ''Bomby the Bombardier Beetle''== The [[young Earth creationist]] [[Duane Gish]], assistant director of the [[Institute for Creation Research]], described the bombardier beetle in his 1977 book ''Dinosaurs: Those Terrible Lizards'', claiming they could not conceivably have [[evolution|evolved]] the various components needed to make the system work, as the components appeared to him to provide no benefit in themselves and therefore the entire system would have to be created at once. He stated that the hydrogen peroxide and hydroquinone would explode on contact, and that the beetle adds an inhibitor to keep this from happening. Then, when threatened, the beetle "squirts in an anti-inhibitor" to start the reaction. As we now know, this is not quite accurate as the beetle instead uses catalysts to cause the reaction to start. Gish blamed a problem of translation leading him to misunderstand his German source, but continued to use his description in debates. At the end of 1980 the [[National Center for Science Education]] - a non-profit organization in Oakland, California, affiliated with the American Association for the Advancement of Science, which defends the teaching of evolutionary biology and opposes the teaching of religious views in science classes in public schools - described the error as well as describing how the mechanism could have gradually evolved through [[natural selection]].<ref>[http://www.ncseweb.org/resources/articles/3955_issue_03_volume_2_number_1__2_21_2003.asp#The%20Bombadier%20Beetle%20Myth%20Exploded The Bombadier Beetle Myth Exploded] – [[National Center for Science Education]] (''Creation/Evolution'' Issue 03, Volume 2, Number 1 - Winter 1981)</ref> This description of the process was used in publications by other authors, from 1981 to 1990.<ref name=to>[http://www.talkorigins.org/faqs/bombardier.html Bombardier Beetles and the Argument of Design] by Mark Isaak, 1997, updated [[May 30]], [[2003]], [[TalkOrigins Archive]], retrieved [[2007-07-09]]</ref><ref name=am>{{Citation | last = Armitage | first =Mark H. | last2 = Mullisen | first2 = Luke | date =April 2003 | year = 2003 | title =Preliminary observations of the pygidial gland of the Bombardier Beetle, Brachinus sp. | publisher =[[Answers in Genesis]] | url =http://www.answersingenesis.org/tj/v17/i1/beetle.asp | accessdate =[[2007-07-09]] }}</ref> A similar argument is set out in the children's book ''Bomby the Bombardier Beetle'' (ages 4–8), published by the Institute for Creation Research in June 1984, and still on sale as of July 2007.<ref>{{Citation | last = Rue | first = Hazel | date =June 1984 | year = 1984 | title =Bomby the Bombardier Beetle | publisher =Institute for Creation Research | isbn =0-932766-13-7 }}</ref><ref name=to/><ref name=am/><ref>{{Citation | last =Angier | first = Natalie | date =February 25, 1985 | year = 1985 | title =Drafting the Bombardier Beetle ^ | publisher =Time Magazine | url =http://www.time.com/time/magazine/article/0,9171,961206-1,00.html | accessdate =[[2007-07-09]] }}</ref> In his 1996 book ''Darwin's Black Box'' [[Michael Behe]] presented the same argument as "[[irreducible complexity]]" which he claimed to have found in various organisms. He discussed the bombardier beetle, but agreed that Darwinian evolution may possibly have been responsible for the formation of the Bombardier Beetle defensive system, as well as creationism.<ref name=am/> == Darwin's experience == During [[Charles Darwin's education#Beetle collecting|Charles Darwin's education]] at the [[University of Cambridge]] he became involved in a national craze for the competitive collecting of beetles. On one occasion in 1828 he stripped bark from a dead tree and caught a rare beetle in each hand, then saw another new species. With the habits of an egg collector, he popped the beetle from his right hand into his mouth and grabbed the other with his free hand. The beetle which he had placed in his mouth, likely a bombardier beetle, "ejected some intensely acrid fluid, which burnt [his] tongue," forcing him to spit it out; he lost the beetle, as well as the third one.<ref>{{cite web|url=http://www.amnh.org/exhibitions/darwin/young/lifelong.php |title=Darwin: Young Naturalist |work=American Museum of Natural History|accessdate=2006-07-12}}</ref> ==References== <div class="references-small"> <references/> </div> == External links == * [http://www.pnas.org/cgi/content/abstract/96/17/9705?ijkey=097c98acbdf7a2ee2d340f97a0459336c9f30c84&keytype2=tf_ipsecsha Proceedings of the National Academy of Sciences article: "Spray aiming in the bombardier beetle: Photographic evidence"] * [http://bugguide.net/node/view/16725 Genus ''Brachinus''--BugGuide.net] * [http://www.answersingenesis.org/creation/v27/i3/bombardier.asp Bombardier Idea from answersingenesis.org] * [http://www.talkorigins.org/faqs/bombardier.html Bombardier Beetles and the Argument of Design from talkorigins.org] * [http://jeb.biologists.org/cgi/content/abstract/203/8/1265 Journal of Experimental Biology "Spray mechanism of the most primitive bombardier beetle (''Metrius contractus'')"] T Eisner, DJ Aneshansley, M Eisner, AB Attygalle, DW Alsop and J Meinwald, Journal of Experimental Biology, Vol 203, Issue 8 1265-1275, Copyright © 2000 by Company of Biologists * [http://www.life-of-science.net/bio--and-nanotechnology/feature/exploding-beetles-suggest-a-new-pressure-relief-valve-and-fluid-discharge-system.html Overview feature about recent research on the fluid discharge mechanism in Bombardier beetles] http://www.talkorigins.org/indexcc/CB/CB310.html http://www.talkorigins.org/faqs/bombardier.html {{Commons|Brachinus}} [[Category:Carabidae]] [[de:Bombardierkäfer]] [[fr:Coléoptère bombardier]] [[he:מפציצנית מרעישה]] [[it:Brachininae]] [[ku:Kêzika fisek]] [[lt:Bombožygiai]]