Preadaptation This website includes a short description of preadaption and a video.
http://www.blackwellpublishing.com/ridley/a-z/Preadaptation.asp
Definition "A small change in structure results in a big change in function" from http://www.blackwellpublishing.com/ridley/a-z/Preadaptation.asp
Another great source-about human preadaptations http://blogs.scientificamerican.com/guest-blog/2013/01/16/universality-of-preadaptation-for-the-human-condition/
It discusses how E.O. Wilson's, The Social Conquest of Earth, describes human preadaptations that lead to the technologically advanced species we are and a highly developed brain.
[Web log message]. (2013, January 16). Retrieved from http://blogs.scientificamerican.com/guest-blog/2013/01/16/universality-of-preadaptation-for-the-human-condition/
According to Wikipedia, preadaptation is synomous with exaptation.