The appendix is the classic vestigial organ that everyone seems to know about. Live Science writes: “In plant-eating vertebrates, the appendix is much larger and its main function is to help digest a largely herbivorous diet. The human appendix is a small pouch attached to the large intestine where it joins the small intestine and does not directly assist digestion. Biologists believe it is a vestigial organ left behind from a plant-eating ancestor.”

Live Science

Editorial Comment: The appendix does not have a primary role in digestion, but that does not make it useless. Its location at the junction of the small and large intestine is a clue to its function, as is the collections of lymphocytes (body defence cells) in its lining.

The appendix is part of a system that determines which microbes are allowed to live in the intestines and which ones are not. The large intestine needs to have a healthy population of harmless bacteria living on its inner surface. Babies develop in a germ-free environment in their mother’s womb so during infancy and childhood the immune system has to learn which microbes can live on the body surfaces and which cannot. Even the good microbes need to be kept in their place and your immune system helps keep them there throughout your life. This means the appendix had a function in the original very good world, and still has this same function. It also means that it does most of its work in the early years of life, and losing it later in life does not affect the overall immune function. There is plenty of other immune tissue around the intestines to compensate for the loss.

Now that the world is no longer very good, the appendix is prone to disease, because our bodies are not as efficient at keeping microbes in their place, and our digestive systems are not as efficient. However, this makes it no different to any other organ that gets diseased and therefore needs to be removed in order to save someone’s life. The fallen nature of the world has also given the appendix another function. When the large bowel becomes inflamed and its population of good bacteria is lost due to outpouring fluid that is part of the inflammatory response to injury and infection, the appendix acts as a “safe house” for good bacteria, which can then repopulate the large bowel when the inflammation is over.

In summary: the appendix is a fully functional, but poorly understood organ, with nothing vestigial about it, which is why surgeons who used to chop out even healthy appendices on the evolutionary assumption it was useless, no longer do so. Of course if they had used the creation based assumption that God made man and we need all our bits they would have saved a lot of healthy people some useless suffering. (Ref. vestigial, gastrointestinal, medicine)

Evidence News, 7 October 2009