Question: why do we have an appendix


  1. My understanding is that we have an appendix because our ancestors ate a lot more grass and it was used as part of the break down of grass. Since we don’t any more it is referred to as a vestigial organ. The main reason for its existence now is to act as a little pocket to hold bacteria in so that if you get a particularly nasty case of diarrhoea you have a pocket of good bacteria ready to repopulate your guts when you start to get over your illness.
    Because it is such a nice place for bacteria to hang out it can easily get inflamed which is why people often have to have them removed.


  2. Hi Horselover,

    It was thought for a long time that it was a vestigial organ. That is an organ that doesn’t really have much current use, but was obviously handy at a time in our past. It was thought that it was an organ ‘left over’ from the cecum.
    However, this is actually not the case. The appendix does appear to have a function, and that is the flushing of the digestive tract with bacteria at times of sickness. A number of species have been identified as having both an appendix and a cecum, so it is not a vestigial organ after all.
    Having said that, its role has certainly diminished from what it once was.