recently, at a local bar, it was brought to my attention that not all people
believe in evolution.  so to prove that evolution is real and people and all
animals evolve i present the example of wisdom teeth.  if it were not for
the advances in dentistry, a larger number of people that develop wisdom teeth
would die from impacted wisdom teeth (ie. they become infected, etc).
thus people who did not form wisdom teeth would become a higher and 
higher percentage of the population.