exaptationn.
/ˌɛksapˈteɪʃn/, /ˌɛɡzapˈteɪʃn/, U.S. /ˌɛksæpˈteɪʃ(ə)n/, /ˌɛɡzæpˈteɪʃ(ə)n/ Biology.
A character or feature which evolved by a process other than selective adaptation for the function it subsequently acquired; the process by which features acquire functions for which they were not originally adapted or selected. Also in extended use.
ΚΠ
1981 New Scientist 24 Dec. 912 A privilege it was, at Professor Stephen Jay Gould's recent Tinbergen lecture, to witness the birth of a new scientific term... ‘Exaptation’ is the word, the companion-piece of adaptation.
1982 S. J. Gould & E. S. Vrba in Paleobiology 8 6/1 We suggest that such characters, evolved for other usages (or for no function at all), and later ‘coopted’ for their current role, be called exaptations... They owe their fitness to features present for other reasons, and are therefore fit (aptus) by reason of (ex) their form, or ex aptus.
1985 Amer. Jrnl. Bot. 72 1712 The ability to tolerate excessively high levels of nickel and other heavy metals may be a physiological exaptation of the genus Calochortus and not necessarily an evolutionary response.
1997 R. Posner Ling. Change in French vii. 299 Morphological markers tend to be comparatively stable, and even outlive their functional usefulness. They can even acquire new functions by the process of exaptation.
2002 N.Y. Times Bk. Rev. 14 Apr. 13/3 Proteins that originally evolved for one function can be co-opted by the cell for another; through such ‘exaptation’, complicated cellular machinery can be built up.
This is a new entry (OED Third Edition, December 2006; most recently modified version published online March 2022).
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n.1981