Fig. 2

A simple example of exaptation and secondary adaptation. A The original and still primary adaptive function of coins is as currency. B A coin co-opted into a new exaptive role as an instant lottery ticket scraper. Coins would always have been capable of scraping tickets, but this function did not become apparent until an environment arose in which instant lottery tickets were abundant. Though functional as scrapers, coins are somewhat difficult to hold and may not reliably be on hand when needed. C A secondary adaptation that enhances the novel function of a coin as a ticket scraper by incorporating it into a keychain that is easier to grip (US Patent #6009590, “Lottery ticket scraper incorporating coin” by K.M. Stanford 2000). In this case, a second preexisting structure (key ring) was co-opted into a function as a carrier for a lottery ticket scraper