I'd like to point out that the appendix does in fact have a purpose. I've posted this a few times, so in short:

The Appendix is full of bacteria.

When humans used to eat raw meat, the appendix would excrete a small amount of the bacteria to stop us from getting sick. Our bodies have since almost forgotten how to do this, since we started cooking our food.

When we are sick with diarrhea and lose the bacteria and cultures naturally found in our intestines, the appendix with give off some bacteria to help rebuild to proper intestinal environment.

If food, worms, fecal matter, or any other foreign object gets caught in the appendix, the bacteria will attack it, causing it to swell and burst (appendicitis).