As if in answer to my questions, my husband found the following on CNN.com today:
The function of the appendix seems related to the massive amount of bacteria populating the human digestive system, according to the study in the Journal of Theoretical Biology. There are more bacteria than human cells in the typical body. Most are good and help digest food.
But sometimes the flora of bacteria in the intestines die or are purged. Diseases such as cholera or amoebic dysentery would clear the gut of useful bacteria. The appendix's job is to reboot the digestive system in that case.
The appendix "acts as a good safe house for bacteria," said Duke surgery professor Bill Parker, a study co-author. Its location _ just below the normal one-way flow of food and germs in the large intestine in a sort of gut cul-de-sac -- helps support the theory, he said.
Also, the worm-shaped organ outgrowth acts like a bacteria factory, cultivating the good germs, Parker said.
In less developed countries, where the appendix may be still useful, the rate of appendicitis is lower than in the U.S., other studies have shown, Parker said.
Read the rest here.