Editing Irreducible complexity (section)

=== Gradual adaptation to new functions ===
{{Main|Exaptation}}
The precursors of complex systems, when they are not useful in themselves, may be useful to perform other, unrelated functions. Evolutionary biologists argue that evolution often works in this kind of blind, haphazard manner in which the function of an early form is not necessarily the same as the function of the later form. The term used for this process is [[exaptation]]. The [[evolution of mammalian auditory ossicles|mammalian middle ear]] (derived from a jawbone) and the [[giant panda|panda]]'s thumb (derived from a wrist bone spur) provide classic examples. A 2006 article in ''Nature'' demonstrates intermediate states leading toward the development of the ear in a [[Devonian]] fish (about 360 million years ago).<ref>{{cite journal |journal= Nature |volume= 439 |pages= 318–21 |date= January 19, 2006 |author1=M. Brazeau |author2=P. Ahlberg |doi= 10.1038/nature04196 |issue= 7074 |title= Tetrapod-like middle ear architecture in a Devonian fish |pmid= 16421569|bibcode= 2006Natur.439..318B|s2cid= 4301561 }}</ref> Furthermore, recent research shows that viruses play a heretofore unexpected role in evolution by mixing and matching genes from various hosts.<ref>{{Cite journal|last=Boto|first=Luis|date=October 28, 2009|title=Horizontal gene transfer in evolution: facts and challenges|journal=Proceedings of the Royal Society B|volume=277|issue=1683|pages=819–827|doi=10.1098/rspb.2009.1679|pmid=19864285|pmc=2842723}}</ref>

Arguments for irreducibility often assume that things started out the same way they ended up—as we see them now. However, that may not necessarily be the case. In the ''Dover'' trial an expert witness for the plaintiffs, Ken Miller, demonstrated this possibility using Behe's mousetrap analogy. By removing several parts, Miller made the object unusable as a mousetrap, but he pointed out that it was now a perfectly functional, if unstylish, [[tie clip]].<ref name="Only" /><ref name=NOVAChapter8>{{cite web |url= https://www.pbs.org/wgbh/nova/transcripts/3416_id_08.html |title= NOVA: Transcripts: Judgment Day: Intelligent Design on Trial Chapter 8 |date= November 13, 2007 |publisher= [[Public Broadcasting Service|PBS]] |access-date= 2008-12-17 |url-status= live |archive-url= https://web.archive.org/web/20081123085214/http://www.pbs.org/wgbh/nova/transcripts/3416_id_08.html |archive-date= November 23, 2008 }}</ref>