Irreducible complexity: Difference between revisions

'''Irreducible complexity''' ('''IC''') is the argument that certain [[biological system]]s with multiple interacting parts would not function if one of the parts were removed, so supposedly could not have [[evolution|evolved]] by successive small modifications from earlier less complex systems through [[natural selection]], which would need all intermediate precursor systems to have been fully functional.<ref name="Behe 1996 p. 39" /> This negative argument is then complemented by the claim that the only alternative explanation is a "purposeful arrangement of parts" inferring design by an intelligent agent.<ref name="bio design classrooms" /> Irreducible complexity has become central to the [[creationism|creationist]] concept of [[intelligent design]] (ID), but the concept of irreducible complexity has been rejected by the [[scientific community]],<ref name="dover_behe_ruling">"We therefore find that Professor Behe's claim for irreducible complexity has been refuted in peer-reviewed research papers and has been rejected by the scientific community at large." [[s:Kitzmiller v. Dover Area School District#E. Application of the Endorsement Test to the ID Policy|4:Whether ID Is Science, in E. Application of the Endorsement Test to the ID Policy, Ruling, Judge John E. Jones III, ''Kitzmiller v. Dover Area School District'']]</ref> which regards intelligent design as [[pseudoscience]].<ref>"True in this latest creationist variant, advocates of so-called intelligent design ... use more slick, pseudoscientific language. They talk about things like "irreducible complexity" {{cite book |author= Shulman, Seth |title= Undermining science: suppression and distortion in the Bush Administration |publisher= University of California Press |location= Berkeley |year= 2006 |page= [https://archive.org/details/underminingscien00shul/page/13 13] |isbn= 978-0-520-24702-4 |url= https://archive.org/details/underminingscien00shul/page/13 }} "for most members of the mainstream scientific community, ID is not a scientific theory, but a creationist pseudoscience."<br />{{cite journal |first= David |last= Mu |title= Trojan Horse or Legitimate Science: Deconstructing the Debate over Intelligent Design |journal= Harvard Science Review |volume= 19 |issue= 1 |date= Fall 2005 |url= http://www.hcs.harvard.edu/~hsr/fall2005/mu.pdf |url-status= dead |archive-url= https://web.archive.org/web/20070724203349/http://www.hcs.harvard.edu/~hsr/fall2005/mu.pdf |archive-date= 2007-07-24 }}<br />{{cite journal |author= Perakh, M |title= Why Intelligent Design Isn't Intelligent — Review of: Unintelligent Design |journal= Cell Biol. Educ. |volume= 4 |issue= 2 |pages= 121–2 |date= Summer 2005 |doi= 10.1187/cbe.05-02-0071 |pmc= 1103713}}<br />Mark D. Decker. College of Biological Sciences, General Biology Program, University of Minnesota [http://www.texscience.org/files/faqs.htm Frequently Asked Questions About the Texas Science Textbook Adoption Controversy] {{webarchive|url= https://web.archive.org/web/20100930160317/http://www.texscience.org/files/faqs.htm |date= 2010-09-30 }} "The Discovery Institute and ID proponents have a number of goals that they hope to achieve using disingenuous and mendacious methods of marketing, publicity, and political persuasion. They do not practice real science because that takes too long, but mainly because this method requires that one have actual evidence and logical reasons for one's conclusions, and the ID proponents just don't have those. If they had such resources, they would use them, and not the disreputable methods they actually use."<br />See also [[list of scientific societies explicitly rejecting intelligent design]]</ref> Irreducible complexity and [[specified complexity]], are the two main arguments used by intelligent-design proponents to support their version of the theological [[teleological argument|argument from design]].<ref name="bio design classrooms" /><ref name="LiveScience- msnbc.com">{{cite web |url= httphttps://www.nbcnews.com/id/9452500wbna9452500 |title= Why scientists dismiss 'intelligent design' – LiveScience |first= Ker |last= Than |date= September 23, 2005 |publisher= [[NBC News]] |access-date= 2010-05-17 }}</ref>

[[Galen]] (1st and 2nd centuries AD) wrote about the large number of parts of the body and their relationships, which observation was cited as evidence for creation.<ref>''De Formatione Foetus''=''The Construction of the Embryo'', chapter 11 in ''Galen: Selected Works'', translated by P. N. Singer, ''The World's Classics'', Oxford, Oxford University Press, 1997 {{ISBN|978-0-19-282450-9}}. One 18th-century reference to Galen is [http://www.anselm.edu/homepage/dbanach/dnr.htm#A13 David Hume ''Dialogues Concerning Natural Religion'', 1779, Part 12]{{webarchive|url=https://web.archive.org/web/20051122134556/http://www.anselm.edu/homepage/dbanach/dnr.htm |date=2005-11-22 }}, §&nbsp;3, page 215. Also see Galen's ''De Usu Partium''=''On the Usefulness of the Parts of the Body'', translated and edited by Margaret Tallmadge May, Ithaca, New York, Cornell University Press, 1968, especially book XVII. For a relevant discussion of Galen and other ancients see pages 121-122121–122, {{cite book |author= Goodman, Lenn Evan |title= Creation and evolution |location= Milton Park, Abingdon, Oxon and New York |publisher= Routledge |year= 2010 |isbn= 978-0-415-91380-5}}</ref> The idea that the interdependence between parts would have implications for the origins of living things was raised by writers starting with [[Pierre Gassendi]] in the mid-17th century<ref>''De Generatione Animalium'', chapter III. Partial translation in: Howard B. Adelmann, ''Marcello Malpighi and the Evolution of Embryology'' Ithaca, New York, Cornell University Press, 1966, volume 2, pages 811-812.</ref> and by [[John Wilkins]] (1614–1672), who wrote (citing Galen), "Now to imagine, that all these things, according to their several kinds, could be brought into this regular frame and order, to which such an infinite number of Intentions are required, without the contrivance of some wise Agent, must needs be irrational in the highest degree."<ref>John Wilkins, ''Of the Principles and Duties of Natural Religion'', London, 1675, book I, chapter 6, page 82 [https://quod.lib.umich.edu/e/eebo/A66053.0001.001/1:5.6?rgn=div2;view=fulltext Early English Books Online]</ref><ref>"The appeal to irreducible complexity goes back more than three centuries. To quote John Wilkins ...", [https://www.3quarksdaily.com/3quarksdaily/2019/02/darwin-does-devolve-sometimes-so-what.html Paul Braterman "Darwin Does Devolve. Sometimes. So What?" 3 Quarks Daily February 25, 2019]</ref> In the late 17th-century, [[Thomas Burnet]] referred to "a multitude of pieces aptly joyn'd" to argue against the [[eternity]] of life.<ref>[http://www.sacred-texts.com/earth/ste/ste07.htm ''The Sacred Theory of the Earth''] {{webarchive|url=https://web.archive.org/web/20071020060523/http://sacred-texts.com/earth/ste/ste07.htm |date=2007-10-20 }}, 2nd edition, London: Walter Kettilby, 1691. Book I Chapter IV page 43</ref> In the early 18th century, [[Nicolas Malebranche]]<ref>{{cite book|first= Nicolas|last= Malebranche|title= De la recherche de la verité: où l'on traite de la nature de l'esprit de l'homme, & de l'usage qu'il en doit faire pour éviter l'erreur dans les sciences|edition= 6ième|location= Paris|publisher= Chez Michel David|year= 1712|url= https://books.google.com/books?id=Gi0_AAAAcAAJ&q=%22d%C3%A9pendent%20mutuellement%22&pg=RA1-PA57}} Livre 6ième, 2ième partie, chapître 4; English translation: {{cite book|first= Nicholas|last= Malebranche|title= The Search After Truth: With Elucidations of The Search After Truth|editor1= Thomas M. Lennon |editor2= Paul J. Olscamp |location= Cambridge|publisher= Cambridge University Press|year= 1997|isbn= 978-0-521-58004-5|url= https://archive.org/details/searchaftertruth0000male|url-access= registration|page= [https://archive.org/details/searchaftertruth0000male/page/465 465]}} Second paragraph from the end of the chapter, on page 465.</ref> wrote "An organized body contains an infinity of parts that mutually depend upon one another in relation to particular ends, all of which must be actually formed in order to work as a whole", arguing in favor of [[preformation]], rather than [[epigenesis (biology)|epigenesis]], of the individual;<ref>Pages 202-204 of {{cite book|first= Andrew |last= Pyle |chapter= Malebranche on Animal Generation: Preexistence and the Microscope |editor= Smith JH |title= The problem of animal generation in early modern philosophy |publisher= Cambridge University Press |location= Cambridge, UK |year= 2006 |pages= 194–214 |isbn= 978-0-521-84077-4 |chapter-url= https://books.google.com/books?id=EyMWhGH4JgIC&q=%22irreducible+complexity%22+intitle%3Aproblem+intitle%3Aof+intitle%3Ageneration+inauthor%3Asmith&pg=PA204|author-link= Andrew Pyle (philosopher) }}</ref> and a similar argument about the origins of the individual was made by other 18th-century students of natural history.<ref>{{cite web|url=http://talkreason.org/articles/chickegg.cfm|title=The Chicken or the Egg|website=talkreason.org|access-date=7 May 2018|url-status=live|archive-url=https://web.archive.org/web/20170429075443/http://www.talkreason.org/articles/chickegg.cfm|archive-date=29 April 2017}}</ref> In his 1790 book, ''[[The Critique of Judgment#Teleology|The Critique of Judgment]]'', [[Immanuel Kant|Kant]] is said by Guyer to argue that "we cannot conceive how a whole that comes into being only gradually from its parts can nevertheless be the cause of the properties of those parts".<ref>This is Guyer's exposition on page 22 of {{cite book|editor= Paul Guyer|title= The Cambridge Companion to Kant|first= Paul|last= Guyer|author-link= Paul Guyer|chapter= Introduction|pages= [https://archive.org/details/cambridgecompani0000unse_i7u7/page/1 1–25]|location= Cambridge|publisher= Cambridge University Press|year= 1992|isbn= 978-0-521-36768-4|chapter-url= https://books.google.com/books?id=pYE5rVzrPNgC&q=%22gradually+from+its+parts%22+intitle%3Acambridge+intitle%3Acompanion+intitle%3Ato+intitle%3Akant+inauthor%3Aguyer&pg=PA22|url= https://archive.org/details/cambridgecompani0000unse_i7u7/page/1}} Guyer adds this parenthetical comment: "(here is where the theory of natural selection removes the difficulty)". See Kant's discussion in section IX of the "First Introduction" to the ''Critique of Judgment'' and in §§&nbsp;61, 64 (where he uses the expression ''wechselsweise abhängt''="reciprocally dependent"), and §&nbsp;66 of "Part Two, First Division". For example, {{cite book |chapter-url= https://books.google.com/books?id=JEXHIcDbBDcC&q=%22reciprocally+dependent%22+intitle%3Acritique+intitle%3Ajudgment+inauthor%3Akant&pg=PA243 |title= Critique of the power of judgment |first= Immanuel |last= Kant |editor1= Paul Guyer |editor2= Eric Matthews |location= Cambridge |publisher= Cambridge University Press |year= 2000 |isbn= 978-0-521-34447-0 |pages= 243–244 |chapter= §&nbsp;64 }} German original {{cite book |title= Kritik der Urtheilskraft |url= https://books.google.com/books?id=6O1Nayo3wWgC&q=akademie+%22wechselsweise+abhängt%22+inauthor:kant&pg=PA371 |volume= 5 |page= 371 |location= Berlin |publisher= Georg Reimer |edition= Königlich Preußischen Akademie der Wissenschaften |series= Kants gesammelte Schriften |year= 1913 |isbn= 978-3-11-001438-9 }}</ref><ref>See also {{cite book|title=Opus Postumum|url=https://archive.org/details/opuspostumumthec00kant|url-access=limited|first=Imanuel|last=Kant|editor=Eckart Förster|translator1=Eckart Förster|translator2=Michael Rosen|location=Cambridge|publisher=Cambridge University Press|year=1993|isbn=0-521-31928-5|page=[https://archive.org/details/opuspostumumthec00kant/page/n125 64]|quote=The definition of an organic body is that it is a body, every part of which is there ''for the sake of the other'' (reciprocally as end and, at the same time, means).}}German original {{cite book |title= Kritik der Urtheilskraft |url= https://books.google.com/books?id=6O1Nayo3wWgC&q=akademie+%22wechselsweise+abhängt%22+inauthor:kant&pg=PA371 |volume= 21 |page= 210|location= Berlin |publisher= Georg Reimer |edition= Königlich Preußischen Akademie der Wissenschaften |series= Kants gesammelte Schriften |isbn=978-3-11-090167-2|date = February 1971}}</ref>

In the late 19th century, in a dispute between supporters of the adequacy of [[natural selection]] and those who held for [[inheritance of acquired characteristics]], one of the arguments made repeatedly by [[Herbert Spencer]], and followed by others, depended on what Spencer referred to as ''co-adaptation'' of ''co-operative'' parts, as in: <blockquote>"We come now to Professor [[August Weismann|Weismann]]'s endeavour to disprove my second thesis — thatthesis—that it is impossible to explain by natural selection alone the co-adaptation of co-operative parts. It is thirty years since this was set forth in 'The Principles of Biology.' In §&nbsp;166, I instanced the enormous horns of the extinct [[Irish elk]], and contended that in this and in kindred cases, where for the efficient use of some one enlarged part many other parts have to be simultaneously enlarged, it is out of the question to suppose that they can have all spontaneously varied in the required proportions."<ref>Page 594 in: {{cite journal|first= Herbert|last= Spencer|title= Weismannism Once More|journal= [[The Contemporary Review]]|date= October 1894|volume= 66 |pages= 592–608}} Another essay of Spencer's treating this concept is: {{cite journal|first= Herbert |last= Spencer |title= The Inadequacy of "Natural Selection" |journal= The Contemporary Review |volume= 63 |year= 1893 |pages= 153–166}} (Part I: February) and pages 439-456 (Part II: March). These essays were reprinted in {{cite book|first= Herbert|last= Spencer|title= The Works of Herbert Spencer|year= 1891|place= London|publisher= Williams and Norgate|volume= 17}} (also Osnabrück: Otto Zeller, 1967). See also part III, Chapter XII, §&nbsp;166, pages 449-457 in: {{cite book |first= Herbert |last= Spencer |title= Principles of Biology |year= 1864 |place= London |publisher= Williams and Norgate|volume= I}} And: {{cite journal|journal= [[The Nineteenth Century (periodical)|The Nineteenth Century]] |first= Herbert|last= Spencer|title= The Factors of Organic Evolution |volume= 19 |year= 1886 |pages= 570–589}} (Part I: April) and pages 749-770 (Part II: May). "Factors" was reprinted in pages 389-466 of {{cite book|first= Herbert|last= Spencer|title= The Works of Herbert Spencer|volume= 13|location= London|publisher= Williams and Norgate|year= 1891}} (also Osnabrück: Otto Zeller, 1967)= volume 1 of ''Essays: Scientific, Political, and Speculative''.</ref><ref>One example of a response was in Section III(γ) pages 32-42 of {{cite book|first= August |last= Weismann |chapter= The Selection theory |pages= 19–65 |title= Darwin and Modern Science: Essays in Commemoration of the Centenary of the Birth of Charles Darwin and of the Fiftieth Anniversary of the Publication of The Origin of Species|chapter-url= https://archive.org/details/in.ernet.dli.2015.42056 |editor= [[Albert Seward]]|location= Cambridge |publisher= Cambridge University Press |year= 1909}} See also Chapter VII, §&nbsp;12(1), pages 237-238 in: {{cite book|first= J. Arthur |last=Thomson|title= Heredity|url= https://archive.org/details/in.ernet.dli.2015.217008|place= London|publisher= John Murray|year= 1908|author-link= J. Arthur Thomson}} Both of these referred to what has become known as the [[Baldwin effect]]. An analysis of both sides of the issue is: {{cite book |first= George John |last=Romanes |title= Darwin and After Darwin: Post-Darwinian Questions, Heredity, Utility |volume= II |chapter= III: Characters as Hereditary and Acquired (continued) |pages= 60–102 |place= London |publisher= Longman, Green |year= 1895|author-link= George John Romanes }}</ref></blockquote> Darwin responded to Spencer's objections in chapter XXV of ''[[The Variation of Animals and Plants Under Domestication]]'' (1868).<ref>{{cite book|title= The Variation of Animals and Plants Under Domestication|first= Charles|last= Darwin|year= 1868|location= London|publisher= John Murray|chapter= XXV. Laws of Variation ''continued'' – Correlated Variability|volume= 2|pages= 321–338|chapter-url= http://darwin-online.org.uk/content/frameset?keywords=co%20ordinated&pageseq=236&itemID=F877.2&viewtype=text|url-status= live|archive-url= https://web.archive.org/web/20150925075611/http://darwin-online.org.uk/content/frameset?keywords=co%20ordinated&pageseq=236&itemID=F877.2&viewtype=text|archive-date= 2015-09-25}} especially page 333 and following.</ref> The history of this concept in the dispute has been characterized: "An older and more religious tradition of idealist thinkers were committed to the explanation of complex adaptive contrivances by intelligent design. ... Another line of thinkers, unified by the recurrent publications of Herbert Spencer, also saw [[co-adaptation]] as a composed, irreducible whole, but sought to explain it by the inheritance of acquired characteristics."<ref>Pages 67-68 in: {{cite journal|first= Mark|last= Ridley|title= Coadapatation and the Inadequacy of Natural Selection|journal= British Journal for the History of Science |volume= 15|issue= 1 |date= March 1982 |pages= 45–68 |doi= 10.1017/S0007087400018938|pmid= 11610981|s2cid= 9704653|author-link= Mark Ridley (zoologist)}}</ref>

In 1985 [[Graham Cairns-Smith|Cairns-Smith]] wrote of "interlocking": "How can a complex collaboration between components evolve in small steps?" and used the analogy of the scaffolding called [[centring|centering]] – used—used to [[arch#Construction|build an arch]] then removed afterwards: "Surely there was 'scaffolding'. Before the multitudinous components of present biochemistry could come to lean together ''they had to lean on something else.''"<ref name="Cairns-Smith, A. G. 1985 https://archive.org/details/sevencluestoorig00cair_0/page/39 39, 58–64">{{cite book |author= Cairns-Smith, A. G. |title= Seven clues to the origin of life: a scientific detective story |publisher= Cambridge University Press |location= Cambridge, UK |year= 1985 |pages= [https://archive.org/details/sevencluestoorig00cair_0/page/39 39, 58–64] |isbn= 978-0-521-27522-4 |url= https://archive.org/details/sevencluestoorig00cair_0/page/39 }}</ref><ref>McShea, Daniel W. and Wim Hordijk. "[https://link.springer.com/article/10.1007%2Fs11692-013-9227-6 Complexity by Subtraction]." ''Evolutionary Biology'' (April 2013). [http://www.worldwidewanderings.net/Professional/Publications/complsub.pdf PDF] {{webarchive|url=https://web.archive.org/web/20130513010713/http://www.worldwidewanderings.net/Professional/Publications/complsub.pdf |date=2013-05-13 }}.</ref> However, neither Muller or Cairns-Smith claimed their ideas as evidence of something supernatural.<ref name="Perakh 2008">{{cite journal |url= http://www.skeptic.com/the_magazine/ |title= Bacteria Flagella Look Like Man-made Machines |first= Mark |last= Perakh |publisher= [[Skeptic (U.S. magazine)]] |year= 2008 |volume= 14 |issue= 3 |access-date= 2008-12-06 |url-status= dead |archive-url= https://web.archive.org/web/20081208185535/http://www.skeptic.com/the_magazine/ |archive-date= 2008-12-08 |author-link= Mark Perakh }}</ref>

In 1985, countering the creationist claims that all the changes would be needed at once, [[Graham Cairns-Smith|Cairns-Smith]] wrote of "interlocking": "How can a complex collaboration between components evolve in small steps?" and used the analogy of the scaffolding called [[centring|centering]] – used—used to [[arch#Construction|build an arch]] then removed afterwards: "Surely there was 'scaffolding'. Before the multitudinous components of present biochemistry could come to lean together ''they had to lean on something else.''"<ref name="Cairns-Smith, A. G. 1985 https://archive.org/details/sevencluestoorig00cair_0/page/39 39, 58–64"/><ref>McShea, Daniel W. and Wim Hordijk. "[https://link.springer.com/article/10.1007%2Fs11692-013-9227-6 Complexity by Subtraction]." ''Evolutionary Biology'' (April 2013). [http://www.worldwidewanderings.net/Professional/Publications/complsub.pdf PDF] {{webarchive|url=https://web.archive.org/web/20130513010713/http://www.worldwidewanderings.net/Professional/Publications/complsub.pdf |date=2013-05-13 }}.</ref> Neither Muller or Cairns-Smith said their ideas were evidence of anything supernatural.<ref name="Perakh 2008"/>

The [[Flagellum|bacterial flagellum]] featured in creation science literature. Morris later claimed that one of their [[Institute for Creation Research]] "scientists (the late Dr. Dick Bliss) was using this example in his talks on creation a generation ago". In December 1992 the creation science magazine ''Creation'' called bacterial flagella "rotary engines", and dismissed the possibility that these "incredibly complicated arrangements of matter" could have "evolved by selection of chance mutations. The alternative explanation, that they were created, is much more reasonable."<ref name="bio design classrooms">{{cite journal | last1=Scott | first1=Eugenie C. | last2=Matzke | first2=Nicholas J. | title=Biological design in science classrooms | journal=Proceedings of the National Academy of Sciences | volume=104 | issue=suppl_1 | date=15 May 2007 | issn=0027-8424 | doi=10.1073/pnas.0701505104 | pages=8669–8676| pmid=17494747 | pmc=1876445 | bibcode=2007PNAS..104.8669S | doi-access=free }}</ref><ref name="creation Rotary engines">{{cite web | title=Rotary engines | website=creation.com | date=December 1992 | url=https://creation.com/rotary-engines |quote=''[[Creation Ministries International|Creation]]'' 15(1):23 | access-date=17 July 2023}}</ref> An article in the [[Creation Research Society]] Magazine for June 1994 called a flagellum a "bacterial nanomachine", forming the "bacterial rotor-flagellar complex" where "it is clear from the details of their operation that nothing about them works unless every one of their complexly fashioned and integrated components are in place", hard to explain by natural selection. The abstract said that in "terms of biophysical complexity, the bacterial rotor-flagellum is without precedent in the living world. .... To evolutionists, the system presents an enigma; to creationists, if offers clear and compelling evidence of purposeful intelligent design."<ref name="Slack 2008 p. 173">{{cite book | last=Slack | first=G. | title=The Battle Over the Meaning of Everything: Evolution, Intelligent Design, and a School Board in Dover, PA | publisher=Wiley | year=2008 | isbn=978-0-470-37931-8 | url=https://books.google.com/books?id=1kpx8HrQ08cC&pg=PA173 | access-date=17 July 2023 | pages=172–173 |quote=an article, predating [the 1996] publication of Darwin's Black Box, the book by Michael Behe in which the idea of 'irreducible complexity' was allegedly hammered out and from which the bacterial flagellum became the molecular poster child for both irreducible complexity and intelligent design. The article, titled 'Not So Blind a Watchmaker,' is in a journal called Creation ''Research Society Quarterly'', an overtly creationist journal published by the Creation Research Societv. .... a picture of none other than our now old friend the bacterial flagellum, accompanied by text that calls it a 'nanomachine,' which sounds a lot like biological machine, and a description that is a pretty good summary statement for Behe's and Minnich's claim for the flagellum's irreducible complexity: 'However, it is clear from the details of [the flagellum's] operation that nothing about them works unless every one of their complexly fashioned and integrated components are in place.' And a little further along in the article, he reads, 'In terms of biophysical complexity, the bacterial rotor flagellum is without precedent in the living world. ...To evolutionists the system presents an enigma. To creationists it offers clear and compelling evidence of purposeful intelligent design.' [When asked whether he would agree this was the same argument that he and Behe had advanced for irreducible complexity, Minnich said] "I don't have any problem with that statement. }}<br>{{cite journal |first=Richard D. |last= Lumsden |title= Not So Blind A Watchmaker |journal= Creation Research Society Quarterly |volume= 31 |issue= 1 |pages= 13–22, quotations from pp. 13, 20 |date= June 1994|url=https://www.public.asu.edu/~jmlynch/origins/documents/lumsden1994.pdf |quote=Received 11 May 1993; Revised 15 September 1993}}</ref>

In 2001, [[Michael Behe]] wrote: "[T]here is an asymmetry between my current definition of irreducible complexity and the task facing natural selection. I hope to repair this defect in future work." Behe specifically explained that the "current definition puts the focus on removing a part from an already functioning system", but the "difficult task facing Darwinian evolution, however, would not be to remove parts from sophisticated pre-existing systems; it would be to bring together components to make a new system in the first place".<ref>{{cite journal |author=Behe, MJ |title=Reply to My Critics: A Response to Reviews of Darwin's Black Box: The Biochemical Challenge to Evolution |journal=Biology and Philosophy |volume=16 |issue=5 |pages=685–709 |date=November 2001 |url=http://friends-of-wisdom.com/readings/Behe2001.pdf |doi=10.1023/A:1012268700496 |s2cid=34945871 |url-status=dead |archive-url=https://web.archive.org/web/20110711040554/http://friends-of-wisdom.com/readings/Behe2001.pdf |archive-date=2011-07-11 }}</ref> In the 2005 ''[[Kitzmiller v. Dover Area School District]]'' trial, Behe testified under oath that he "did not judge [the asymmetry] serious enough to [have revised the book] yet."<ref>[http://www.talkorigins.org/faqs/dover/day12am2.html Behe's testimony in ''Kitzmiller v. Dover''] {{webarchive|url=https://web.archive.org/web/20060629222457/http://www.talkorigins.org/faqs/dover/day12am2.html |date=2006-06-29 }}</ref>

In his 2008 book ''[[Only A Theory]]'', biologist [[Kenneth R. Miller]] challenges Behe's claim that the mousetrap is irreducibly complex.<ref name=Only /> Miller observes that various subsets of the five components can be devised to form cooperative units, ones that have different functions from the mousetrap and so, in biological terms, could form functional [[spandrel (biology)|spandrels]] before being adapted to the new function of catching mice. In an example taken from his high school experience, Miller recalls that one of his classmates<blockquote>...struck upon the brilliant idea of using an old, broken mousetrap as a spitball catapult, and it worked brilliantly.... It had worked perfectly as something other than a mousetrap.... my rowdy friend had pulled a couple of parts --probablyparts—probably the hold-down bar and catch-- offcatch—off the trap to make it easier to conceal and more effective as a catapult... [leaving] the base, the spring, and the hammer. Not much of a mousetrap, but a helluva spitball launcher.... I realized why [Behe's] mousetrap analogy had bothered me. It was wrong. The mousetrap is not irreducibly complex after all.<ref name=Only>{{cite book |title= Only A Theory |url= https://archive.org/details/onlytheory00kenn |url-access= limited |first= Kenneth R. |last= Miller |location= New York |year= 2008 |publisher= Viking Penguin |pages= [https://archive.org/details/onlytheory00kenn/page/54 54]–55 |isbn= 978-0-670-01883-3}}</ref></blockquote>

'''Evolution from type three secretion systems'''. The basal body of the flagella has been found to be similar to the [[Type three secretion system|Type III secretion system]] (TTSS), a needle-like structure that pathogenic germs such as ''[[Salmonella]]'' and ''[[Yersinia pestis]]'' use to inject [[toxin]]s into living [[eukaryote]] cells.<ref name="Flagellum Unspun">Miller, Kenneth R. [http://www.millerandlevine.com/km/evol/design2/article.html The Flagellum Unspun: The Collapse of "Irreducible Complexity"] {{webarchive|url=https://web.archive.org/web/20140214024810/http://www.millerandlevine.com/km/evol/design2/article.html |date=2014-02-14 }} with reply here {{cite web |url=http://www.designinference.com/documents/2003.02.Miller_Response.htm |title=The Bacterial Flagellum: Still Spinning Just Fine |access-date=2006-04-26 |url-status=dead |archive-url=https://web.archive.org/web/20060403013818/http://designinference.com/documents/2003.02.Miller_Response.htm |archive-date=2006-04-03 }}</ref><ref>{{cite journal |last1=Pallen |first1=M.J. |last2=Matzke |first2=N.J. |year=2006 |title=From ''The Origin of Species'' to the origin of bacterial flagella |journal=Nature Reviews Microbiology |volume=4 |issue= 10|pages=784–790 |doi=10.1038/nrmicro1493 |pmid=16953248|s2cid=24057949 }}</ref> The needle's base has ten elements in common with the flagellum, but it is missing forty of the proteins that make a flagellum work.<ref>[https://www.youtube.com/watch?v=RQQ7ubVIqo4 Kenneth Miller's The Collapse of Intelligent Design: Section 5 Bacterial Flagellum] {{webarchive|url=https://web.archive.org/web/20161017080729/https://www.youtube.com/watch?v=RQQ7ubVIqo4 |date=2016-10-17 }} (Case Western Reserve University, 2006 January 3)</ref> The TTSS system negates Behe's claim that taking away any one of the flagellum's parts would prevent the system from functioning. On this basis, [[Kenneth R. Miller|Kenneth Miller]] notes that, "The parts of this supposedly irreducibly complex system actually have functions of their own."<ref>[https://web.archive.org/web/20071010035647/http://debatebothsides.com/showthread.php?t=38338 Unlocking cell secrets bolsters evolutionists] (Chicago Tribune, 2006 February 13)</ref><ref>[http://www.talkdesign.org/faqs/flagellum.html Evolution in (Brownian) space: a model for the origin of the bacterial flagellum] {{webarchive|url=https://web.archive.org/web/20160919205453/http://www.talkdesign.org/faqs/flagellum.html |date=2016-09-19 }} (Talk Design, 2006 September)</ref> Studies have also shown that similar parts of the flagellum in different bacterial species can have different functions despite showing evidence of common descent, and that certain parts of the flagellum can be removed without eliminating its functionality.<ref>{{cite book |last1=Egelman |first1=E. H. |title=Intelligent Design A2 – Maloy, Stanley |journal=Brenner's Encyclopedia of Genetics (Second Edition)|date=1 January 2013 |pages=112–114 |publisher=Academic Press |doi=10.1016/B978-0-12-374984-0.00806-8|isbn=978-0-08-096156-9 }}</ref> Behe responded to Miller by asking "why doesn't he just take an appropriate bacterial species, knock out the genes for its flagellum, place the bacterium under selective pressure (for mobility, say), and experimentally produce a flagellum — orflagellum—or any equally complex system — insystem—in the laboratory?"<ref>{{Cite web |last=Michael |first=Behe |author-link=Michael Behe |date=2016-10-27 |title=Philosophical Objections to Intelligent Design: A Response to Critics |url=https://evolutionnews.org/2016/10/philosophical_o/ |access-date=2022-10-12 |website=Evolution News |language=en-US}}</ref> However a laboratory experiment has been performed where "immotile strains of the bacterium Pseudomonas fluorescens that lack flagella [...] regained flagella within 96 hours via a two-step evolutionary pathway", concluding that "natural selection can rapidly rewire regulatory networks in very few, repeatable mutational steps".<ref name=":0">{{Cite journal |last1=Taylor |first1=Tiffany B. |last2=Mulley |first2=Geraldine |last3=Dills |first3=Alexander H. |last4=Alsohim |first4=Abdullah S. |last5=McGuffin |first5=Liam J. |last6=Studholme |first6=David J. |last7=Silby |first7=Mark W. |last8=Brockhurst |first8=Michael A. |last9=Johnson |first9=Louise J. |last10=Jackson |first10=Robert W. |date=2015-02-27 |title=Evolution. Evolutionary resurrection of flagellar motility via rewiring of the nitrogen regulation system |url=https://pubmed.ncbi.nlm.nih.gov/25722415/ |journal=Science |volume=347 |issue=6225 |pages=1014–1017 |doi=10.1126/science.1259145 |issn=1095-9203 |pmid=25722415|s2cid=206561157 |hdl=10871/16523 |hdl-access=free }}</ref>

Behe argues that the theory that irreducibly complex systems could not have evolved can be falsified by an experiment where such systems are evolved. For example, he posits taking bacteria with no [[flagella|flagellum]] and imposing a selective pressure for mobility. If, after a few thousand generations, the bacteria evolved the bacterial flagellum, then Behe believes that this would refute his theory.<ref>{{Cite web|url=https://evolutionnews.org/2016/10/philosophical_o/|title=Philosophical Objections to Intelligent Design: A Response to Critics|last=Behe|first=Michael|date=October 27, 2016|website=Evolution News & Science Today|access-date=August 17, 2018}}</ref>{{primary source inline|date=August 2018}} This has been done: a laboratory experiment has been performed where "immotile strains of the bacterium ''Pseudomonas fluorescens'' that lack flagella [...] regained flagella within 96 hours via a two-step evolutionary pathway", concluding that "natural selection can rapidly rewire regulatory networks in very few, repeatable mutational steps".<ref name=":0" />{{Update inline|date=December 2023|reason=For reactions, probably}}

Other critics take a different approach, pointing to experimental evidence that they consider falsification of the argument for intelligent design from irreducible complexity. For example, [[Kenneth R. Miller|Kenneth Miller]] describes the lab work of Barry G. Hall on [[Escherichia coli|''E. coli'']] as showing that "Behe is wrong".<ref>{{cite book |author= Miller, K |title= Finding Darwin's God: a scientist's search for common ground between God and evolution |publisher= Cliff Street Books |location= New York |year= 1999 |isbn= 978-0-06-093049-3}}</ref>

[[Eugenie Scott]] and [[Glenn Branch]] of the [[National Center for Science Education]] note that intelligent design arguments from irreducible complexity rest on the false assumption that a lack of knowledge of a natural explanation allows intelligent design proponents to assume an intelligent cause, when the proper response of scientists would be to say that we don'tdo not know, and further investigation is needed.<ref>[[Eugenie C. Scott]] and Glenn Branch, [http://ncseweb.org/creationism/general/intelligent-design-not-accepted-by-most-scientists "Intelligent Design" Not Accepted by Most Scientists] {{webarchive|url=https://web.archive.org/web/20090330203658/http://ncseweb.org/creationism/general/intelligent-design-not-accepted-by-most-scientists |date=2009-03-30 }}, National Center for Science Education website, September 10, 2002.</ref> Other critics describe Behe as saying that evolutionary explanations are not detailed enough to meet his standards, while at the same time presenting intelligent design as exempt from having to provide any positive evidence at all.<ref>{{cite web |url=http://www.patheos.com/blogs/daylightatheism/essays/darwins-black-box/ |title=Darwin's Black Box by Michael Behe |access-date=2015-07-15 |url-status=live |archive-url=https://web.archive.org/web/20150715212827/http://www.patheos.com/blogs/daylightatheism/essays/darwins-black-box/ |archive-date=2015-07-15 }}</ref><ref>Amerikanbeat.net: A Critique of Behe, Dembski on "Irreducible Complexity"[https://web.archive.org/web/20100910063051/http://amerikanbeat.net/contact-amerikanbeat/a-critique-of-behe-dembski-on-%E2%80%9Cirreducible-complexity%E2%80%9D/]</ref>

At the 2005 ''[[Kitzmiller v. Dover Area School District]]'' trial, expert witness testimony defending ID and IC was given by Behe and Scott Minnich, who had been one of the "Johnson-Behe cadre of scholars" at Pajaro Dunes in 1993, was prominent in ID,<ref name=bsr06>{{cite web |url=http://sciencereview.berkeley.edu/articles/issue10/evolution.pdf |title=In the matter of Berkeley v. Berkeley |access-date=3 November 2007 | archive-url=https://web.archive.org/web/20060901093543/http://sciencereview.berkeley.edu/articles/issue10/evolution.pdf | archive-date=1 September 2006 |author=Michelangelo D'Agostino |date=Spring 2006 |work=Berkeley Science Review |pages=31–35 |quote=Two years later, Johnson organized a meeting at Pajaro Dunes near Monterey to bring like-minded thinkers together. Its participants would become the major public figures in intelligent design: Scott Minnich and Michael Behe, who would testify on behalf of ID in Dover, ..... }} (also {{cite web | title=In the matter of Berkeley v. Berkeley | website=The Berkeley Science Review: Read: Articles | date=1 September 2006 | url=http://sciencereview.berkeley.edu/articles.php?issue=10&article=evolution | archive-url=https://web.archive.org/web/20060901072446/http://sciencereview.berkeley.edu/articles.php?issue=10&article=evolution | archive-date=1 September 2006 | url-status=dead | access-date=23 July 2023}})</ref> and was now a tenured associate professor in microbiology at the [[University of Idaho]].<ref name="TalkOrigins Archive day20pm 1">{{cite web | title=Kitzmiller v. Dover: Day 20, PM, Part 1: Scott Minnich | website=TalkOrigins Archive | url=http://www.talkorigins.org/faqs/dover/day20pm.html | access-date=28 July 2023}}</ref> Behe conceded that there are no peer-reviewed papers supporting his claims that complex [[molecular]] systems, like the bacterial flagellum, the blood-clotting cascade, and the immune system, were intelligently designed nor are there any peer-reviewed articles supporting his argument that certain complex molecular structures are "irreducibly complex."<ref name="Kitzmiller_ruling_ID_science" /> There was extensive discussion of IC arguments about the bacterial flagellum, first published in Behe's [[Darwin's Black Box|1996 book]], and when Minnich was asked if similar claims in a 1994 [[Creation Research Society]] article presented the same argument, Minnich said he didn'tdid not have any problem with that statement.<ref name="Slack 2008 p. 173" /><ref name="TalkOrigins Archive day20pm 2">{{cite web | title=Kitzmiller v. Dover: Day 20, PM, Part 2: Scott Minnich | website=TalkOrigins Archive | url=http://www.talkorigins.org/faqs/dover/day20pm2.html | access-date=29 July 2023|quote=Q. Now, you and Dr. Behe both, or together, you make the same claim, the claim of irreducible complexity? A. Correct. Q. And essentially if I understand your contention, it is that an irreducibly complex system is one in which it cannot function unless all the parts are there, and you take away one part and the system ceases to function, correct? A. Correct. Q. And the point that you're trying make for purposes of evolution is that irreducibly complex systems in your view cannot evolve? A. I think it's a problem for evolution. ..... Q. Dr. Minnich, I'm showing you a publication of the Creation research Society Quarterly from June of 1994. Do you see that? ... ... I'd like you to agree with me, to know whether you agree with me that that is the same argument that you have advanced here today in your direct testimony. A. Right, I mean in terms of -- I don't have any problem with that statement. ...}}</ref>

*[httphttps://www.discovery.org/scriptsa/viewDB3419/index.php?command=view&id=3419 How to Explain Irreducible Complexity -- A Lab Manual] [[Discovery Institute]]

* [httphttps://www.asa3.org/ASA/education/origins/ic-cr.htm Irreducible Complexity: Definition & Evaluation] by Craig Rusbult, Ph.D.

*[httphttps://www.pdcnet.org/collection/show?id=philo_2001_0004_0001_0054_0067&file_type=pdf Behe, Biochemistry, and the Invisible Hand]

*[[Kenneth Einar Himma|Himma, Kenneth Einar]]. [httphttps://www.iep.utm.edu/ddesign-arguments-for-existence-of-god/design.htm Design Arguments for the Existence of God]. ''Internet Encyclopedia of Philosophy'': 2. Contemporary Versions of the Design Argument, a. The Argument from Irreducible Biochemical Complexity

*[httphttps://ncse.com/creationism/legalngo/kitzmiller-trial-transcripts ''Kitzmiller vs. Dover'' transcripts]

*[httphttps://www.abc.net.au/science/articles/2015/07/07/4251468.htm The bacterial flagellar motor: brilliant evolution or intelligent design?] Matt Baker, [[Australian Broadcasting Corporation|ABC]] Science, 7 July 2015

*[httphttps://articleswww.chicagotribune.com/2006-/02-/13/news/0602130210_1_intelligentunlocking-designcell-michaelsecrets-behebolsters-dover-caseevolutionists/ Unlocking cell secrets bolsters evolutionists] (''[[Chicago Tribune]]'')