preadaptation

:  a character or the condition of possessing a character that takes on a function when none previously existed or that differs from its original function :  exaptation This principle of evolution is sometimes called preadaptation. There's no foresight involved, though—simply the lucky coincidence that a feature that evolved to do one thing may turn out later to do another thing even better. — Carl Zimmer ◆While the newer term exaptation has been widely adopted, preadaptation continues to be acceptable in current usage with both terms showing comparable frequency of usage.