Monday word: exaptation

[ersatz-read.livejournal.com]

exaptation (ĕg′zăp-tā′shən), noun

1. A process in which a feature acquires a function that was not acquired through natural selection.
2. A feature having a function for which it was not originally adapted.
3. A morphological or physiological feature that predisposes an organism to adapt to a different environment or lifestyle.

Etymology:  coined in the early 1980s by Stephen Jay Gould and Elizabeth Vrba, from ex + adaptation. 

I ran across the word in this article about goldfish.  And here is the Wikipedia article.  And, a Scentific American article.