47
edits
Changes
Jump to navigation
Jump to search
Line 24:
Line 24: − + +
Irreducible complexity (view source)
Revision as of 16:30, December 21, 2011
, 16:30, December 21, 2011no edit summary
:Irreducible complexity is a "single system which is composed of several interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning."
:Irreducible complexity is a "single system which is composed of several interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning."
It is therefore a state of interacting components that could not function without all its parts. In particular, the term is used by proponents of [[intelligent design]] to argue that irreducibly complex biological systems cannot evolve.
It is therefore a state of interacting components that could not function without all its parts. In particular, the term is used by proponents of [[intelligent design]] to argue that irreducibly complex biological systems cannot evolve. However Behe himself had to admit that the argument of irreducible complexity does not fully disprove evolution:
{{Cquote|However, commentary by Robert Pennock and others has made me realize that there is a weakness in that view of irreducible complexity. The current definition puts the focus on removing a part from an already-functioning system. Thus, seeking a counterexample to irreducible complexity, in Tower of Babel Pennock writes about a part in a sophisticated chronometer, whose origin is simply assumed, which breaks to give a system that he posits can nonetheless work in a simpler watch in a less demanding environment. 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. Thus there 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.<ref>[http://www.springerlink.com/content/g527h45501l632v8/fulltext.pdf Reply to My Critics: A Response to Reviews of Darwin’s Black Box] Michael Behe, 2001</ref>}}
The most commonly used examples of irreducibly complex biological systems are the human compound eye, the [[blood clotting cascade]], and the bacterial [[flagellum]]. Kenneth R. Miller describes hypothetical precursors to the flagellum's being used as ionic channels within [[bacteria]], known as the ''Type III Secretory System''.<ref>[http://www.millerandlevine.com/km/evol/design2/article.html The Flagellum Unspun]</ref> However, Professor Behe counters that Miller's criticism of his work is flawed. <ref>http://www.arn.org/docs/behe/mb_trueacidtest.htm</ref> Critics, including biology professor John McDonald, have countered Behe's toy model, the mouse trap, used to illustrate the concept. McDonald produced examples of how he considered the mousetrap to be "easy to reduce", eventually to a single part.<ref name=trap>[http://udel.edu/~mcdonald/mousetrap.html A reducibly complex mousetrap] (graphics-intensive, requires [[JavaScript]])</ref> <!--Critics consider that most, or all, of the examples were based on misunderstandings of the workings of the biological systems in question, and consider the low quality of these examples excellent evidence for the argument from ignorance.-->However, Professor Behe disputes the criticism of John McDonald. <ref>http://www.arn.org/docs/behe/mb_mousetrapdefended.htm</ref>
The most commonly used examples of irreducibly complex biological systems are the human compound eye, the [[blood clotting cascade]], and the bacterial [[flagellum]]. Kenneth R. Miller describes hypothetical precursors to the flagellum's being used as ionic channels within [[bacteria]], known as the ''Type III Secretory System''.<ref>[http://www.millerandlevine.com/km/evol/design2/article.html The Flagellum Unspun]</ref> However, Professor Behe counters that Miller's criticism of his work is flawed. <ref>http://www.arn.org/docs/behe/mb_trueacidtest.htm</ref> Critics, including biology professor John McDonald, have countered Behe's toy model, the mouse trap, used to illustrate the concept. McDonald produced examples of how he considered the mousetrap to be "easy to reduce", eventually to a single part.<ref name=trap>[http://udel.edu/~mcdonald/mousetrap.html A reducibly complex mousetrap] (graphics-intensive, requires [[JavaScript]])</ref> <!--Critics consider that most, or all, of the examples were based on misunderstandings of the workings of the biological systems in question, and consider the low quality of these examples excellent evidence for the argument from ignorance.-->However, Professor Behe disputes the criticism of John McDonald. <ref>http://www.arn.org/docs/behe/mb_mousetrapdefended.htm</ref>