Irreducible complexity

Irreducible complexity (IC) is the argument that certain biological systems with multiple interacting parts would not function if one of the parts were removed, so supposedly could not have 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.^[1] 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.^[2] Irreducible complexity has become central to the creationist concept of intelligent design (ID), but the concept of irreducible complexity has been rejected by the scientific community,^[3] which regards intelligent design as pseudoscience.^[4] Irreducible complexity and specified complexity, are the two main arguments used by intelligent-design proponents to support their version of the theological argument from design.^[2]^[5]

The central concept, of biological complexity too improbable to have evolved by chance natural processes, was already featured in creation science.^[6]^[7] The 1989 school textbook Of Pandas and People introduced the alternative terminology of intelligent design, the 1993 edition was revised to include a variation of the same argument: it was later shown that these revisions were written by Michael Behe, a professor of biochemistry at Lehigh University.^[2]

Behe introduced the expression irreducible complexity along with a full account of his arguments in his 1996 book Darwin's Black Box, and he said it made evolution through natural selection of random mutations impossible, or extremely improbable.^[2]^[1] This was based on the mistaken assumption that evolution relies on improvement of existing functions, ignoring how complex adaptations originate from changes in function, and disregarding published research.^[2] Evolutionary biologists have published rebuttals showing how systems discussed by Behe can evolve,^[8]^[9] and examples documented through comparative genomics show that complex molecular systems are formed by the addition of components as revealed by different temporal origins of their proteins.^[10]^[11]

In the 2005 Kitzmiller v. Dover Area School District trial, Behe gave testimony on the subject of irreducible complexity. The court found 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."^[3]

^ ^a ^b Behe, M.J. (2006). Darwin's Black Box: The Biochemical Challenge to Evolution. Touchstone book (2 ed.). Free Press. p. 39. ISBN 978-0-684-82754-4. Retrieved 16 July 2023. By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution. Since natural selection can only choose systems that are already working, then if a biological system cannot be produced gradually it would have to arise as an integrated unit, in one fell swoop, for natural selection to have anything to act on. (originally published 1996).
^ ^a ^b ^c ^d ^e Cite error: The named reference bio design classrooms was invoked but never defined (see the help page).
^ ^a ^b "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." 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
^ "True in this latest creationist variant, advocates of so-called intelligent design ... use more slick, pseudoscientific language. They talk about things like "irreducible complexity" Shulman, Seth (2006). Undermining science: suppression and distortion in the Bush Administration. Berkeley: University of California Press. p. 13. ISBN 978-0-520-24702-4. "for most members of the mainstream scientific community, ID is not a scientific theory, but a creationist pseudoscience."
Mu, David (Fall 2005). "Trojan Horse or Legitimate Science: Deconstructing the Debate over Intelligent Design" (PDF). Harvard Science Review. 19 (1). Archived from the original (PDF) on 2007-07-24.
Perakh, M (Summer 2005). "Why Intelligent Design Isn't Intelligent — Review of: Unintelligent Design". Cell Biol. Educ. 4 (2): 121–2. doi:10.1187/cbe.05-02-0071. PMC 1103713.
Mark D. Decker. College of Biological Sciences, General Biology Program, University of Minnesota Frequently Asked Questions About the Texas Science Textbook Adoption Controversy Archived 2010-09-30 at the Wayback Machine "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."
See also list of scientific societies explicitly rejecting intelligent design
^ Than, Ker (September 23, 2005). "Why scientists dismiss 'intelligent design' – LiveScience". NBC News. Retrieved 2010-05-17.
^ Scott 2009, p. 126, Behe's idea of irreducible complexity was anticipated in creation science; much as in Paley's conception, creation science proponents hold that structures too complex to have occurred 'by chance' require special creation (Scott and Matzke 2007)."
^ Forrest & Gross 2007, p. 78.
^ Cite error: The named reference thornton2006 was invoked but never defined (see the help page).
^ Cite error: The named reference Redundant Complexity was invoked but never defined (see the help page).
^ Finnigan, Gregory C.; Hanson-Smith, Victor; Stevens, Tom H.; Thornton, Joseph W. (2012). "Evolution of increased complexity in a molecular machine". Nature. 481 (7381): 360–364. Bibcode:2012Natur.481..360F. doi:10.1038/nature10724. PMC 3979732. PMID 22230956.
^ Del Bem, Luiz Eduardo V.; Vincentz, Michel GA (5 November 2010). "Evolution of xyloglucan-related genes in green plants". BMC Evolutionary Biology. 10: 341. doi:10.1186/1471-2148-10-341. PMC 3087550. PMID 21054875.

[Behe_1996_p._39-1] Behe, M.J. (2006). Darwin's Black Box: The Biochemical Challenge to Evolution. Touchstone book (2 ed.). Free Press. p. 39. ISBN 978-0-684-82754-4. Retrieved 16 July 2023. By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution. Since natural selection can only choose systems that are already working, then if a biological system cannot be produced gradually it would have to arise as an integrated unit, in one fell swoop, for natural selection to have anything to act on. (originally published 1996).

[bio_design_classrooms-2] Cite error: The named reference bio design classrooms was invoked but never defined (see the help page).

[dover_behe_ruling-3] "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." 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

[4] "True in this latest creationist variant, advocates of so-called intelligent design ... use more slick, pseudoscientific language. They talk about things like "irreducible complexity" Shulman, Seth (2006). Undermining science: suppression and distortion in the Bush Administration. Berkeley: University of California Press. p. 13. ISBN 978-0-520-24702-4. "for most members of the mainstream scientific community, ID is not a scientific theory, but a creationist pseudoscience."
Mu, David (Fall 2005). "Trojan Horse or Legitimate Science: Deconstructing the Debate over Intelligent Design" (PDF). Harvard Science Review. 19 (1). Archived from the original (PDF) on 2007-07-24.
Perakh, M (Summer 2005). "Why Intelligent Design Isn't Intelligent — Review of: Unintelligent Design". Cell Biol. Educ. 4 (2): 121–2. doi:10.1187/cbe.05-02-0071. PMC 1103713.
Mark D. Decker. College of Biological Sciences, General Biology Program, University of Minnesota Frequently Asked Questions About the Texas Science Textbook Adoption Controversy Archived 2010-09-30 at the Wayback Machine "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."
See also list of scientific societies explicitly rejecting intelligent design

[LiveScience-_msnbc.com-5] Than, Ker (September 23, 2005). "Why scientists dismiss 'intelligent design' – LiveScience". NBC News. Retrieved 2010-05-17.

[Scott_2009_p._126-6] Scott 2009, p. 126, Behe's idea of irreducible complexity was anticipated in creation science; much as in Paley's conception, creation science proponents hold that structures too complex to have occurred 'by chance' require special creation (Scott and Matzke 2007)."

[FOOTNOTEForrestGross200778-7] Forrest & Gross 2007, p. 78.

[thornton2006-8] Cite error: The named reference thornton2006 was invoked but never defined (see the help page).

[Redundant_Complexity-9] Cite error: The named reference Redundant Complexity was invoked but never defined (see the help page).

[10] Finnigan, Gregory C.; Hanson-Smith, Victor; Stevens, Tom H.; Thornton, Joseph W. (2012). "Evolution of increased complexity in a molecular machine". Nature. 481 (7381): 360–364. Bibcode:2012Natur.481..360F. doi:10.1038/nature10724. PMC 3979732. PMID 22230956.

[11] Del Bem, Luiz Eduardo V.; Vincentz, Michel GA (5 November 2010). "Evolution of xyloglucan-related genes in green plants". BMC Evolutionary Biology. 10: 341. doi:10.1186/1471-2148-10-341. PMC 3087550. PMID 21054875.

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