The incidence of appendicitis is highest among adolescents and young adults (13–40 years of age) ( Source : World Journal of Surgery)
Because the appendix has no known function (it's considered a vestigial organ) and since the disease has a fatality rate of 0.30 - 0.37% ( Source : Postgraduate Medical Journal), evolutionary theory would suggest that appendicitis should have long ago disappeared.
To sum up : The appendix has no known beneficial function and yet it predominantly kills those at breeding age. Its prevalence is in an apparent conflict with evolutionary theory.
Note: The foregoing assumes that the tendency to develop appendicitis has a genetic link - which is as yet unproved.
Note: This article is in the 'Awaiting Detail' section. Needs cited source for assertion.