Editing Irreducible complexity (section)

==== 20th century ====
[[Hermann Joseph Muller|Hermann Muller]], in the early 20th century, discussed a concept similar to irreducible complexity. However, far from seeing this as a problem for evolution, he described the "interlocking" of biological features as a consequence to be expected of evolution, which would lead to irreversibility of some evolutionary changes.<ref name="Muller_1918">{{cite journal |author= Muller, HJ |title= Genetic variability, twin hybrids and constant hybrids, in a case of balanced lethal factors |journal= Genetics |volume= 3 |issue= 5 |pages= 422–99 |year= 1918 |doi= 10.1093/genetics/3.5.422 |url= http://www.genetics.org/cgi/reprint/3/5/422 |pmid= 17245914 |pmc= 1200446 |url-status= dead |archive-url= https://web.archive.org/web/20070518220445/http://www.genetics.org/cgi/reprint/3/5/422 |archive-date= 2007-05-18 |access-date= 2006-10-31 }}, especially pages 463–4.</ref> He wrote, "Being thus finally woven, as it were, into the most intimate fabric of the organism, the once novel character can no longer be withdrawn with impunity, and may have become vitally necessary."<ref>{{cite journal |author= Muller, HJ |title= Reversibility in evolution considered from the standpoint of genetics |journal= Biological Reviews of the Cambridge Philosophical Society |volume= 14 |issue= 3 |pages= 261–80, quotation from 272 |year= 1939 |doi=10.1111/j.1469-185x.1939.tb00934.x |s2cid= 85668728 }}</ref>

In 1975 [[Thomas H. Frazzetta]] published a book-length study of a concept similar to irreducible complexity, explained by gradual, step-wise, non-teleological evolution. Frazzetta wrote: <blockquote>"A complex adaptation is one constructed of ''several'' components that must blend together operationally to make the adaptation 'work'. It is analogous to a machine whose performance depends upon careful cooperation among its parts. In the case of the machine, no single part can greatly be altered without changing the performance of the entire machine."</blockquote> The machine that he chose as an analog is the [[Peaucellier–Lipkin linkage]], and one biological system given extended description was the jaw apparatus of a python. The conclusion of this investigation, rather than that evolution of a complex adaptation was impossible, "awed by the adaptations of living things, to be stunned by their complexity and suitability", was "to accept the inescapable but not humiliating fact that much of mankind can be seen in a tree or a lizard."<ref>T. H. Frazzetta, ''Complex Adaptations in Evolving Populations'', Sunderland, Massachusetts: Sinauer Associates, 1975. {{ISBN|0-87893-194-5}}. Referencing pages 3, 4-7, 7-20, and xi, respectively.</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 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>

An early concept of irreducibly complex systems comes from [[Ludwig von Bertalanffy]] (1901–1972), an Austrian biologist.<ref>Ludwig von Bertalanffy (1952). ''Problems of Life: An Evaluation of Modern Biological and Scientific Thought, pg 148'' {{ISBN|1-131-79242-4}}</ref> He believed that complex systems must be examined as complete, [[irreducibility|irreducible]] systems in order to fully understand how they work. He extended his work on biological complexity into a general theory of systems in a book titled ''[[systems theory|General Systems Theory]]''.

After [[James Watson]] and [[Francis Crick]] published the structure of [[DNA]] in the early 1950s, General Systems Theory lost many of its adherents in the physical and biological sciences.<ref>{{cite book |author= Monod, Jacques |title= Chance and necessity: an essay on the natural philosophy of modern biology |publisher= Vintage Books |location= New York |year= 1972 |isbn= 978-0-394-71825-5 |url= https://archive.org/details/chancenecessity00mono }}</ref>
However, [[systems theory]] remained popular in the social sciences long after its demise in the physical and biological sciences.