More musings on our ‘useless’ appendix

A not-so-recent study on the pattern of the appendix among our alleged primate ‘cousins’ showed that, even using evolutionary assumptions, it cannot be a degenerate evolutionary structure.

by and Shaun Doyle

Photo wikipedia Appendix.

Evolutionists often still use our appendix as a classical example of a vestigial or degenerate organ, an evolutionary ‘leftover’—despite much evidence to the contrary.

Creationists have repeatedly highlighted the fact that the appendix is full of lymphoid tissue (to do with the immune system, like that in the tonsils and the ‘glands’ under our armpits, for example).1,2,3 In principle, therefore, even if we did not have any idea what its function might be, it was highly unlikely to turn out to have none. Creationists have also cited various studies and lines of evidence indicating that the appendix’s function is, not surprisingly, likely to have to do with the immunological control of organisms in the gut.4

And that, like the thymus gland (also once thought to be a ‘useless leftover’) its chief function is probably over with well before adulthood is reached.

Recent studies have shown that the appendix may serve a reciprocal probiotic function as a ‘good safe house for bacteria’.5

Since the appendix is a cul-de-sac at the beginning of the material flow of the colon, it enables the gut flora cultivated in the appendix to populate the colon with the natural flow of material through the colon. The small worm-like shape of the appendix also restricts access and allows the bacteria a ‘safe haven’ to grow.

But appendicitis … ?

To bolster the ‘useless’ idea, one still hears the argument that one is more likely to die if one still has an appendix as opposed to having had it removed. But careful thought should have raised the obvious question: since most appendicitis occurs before the age of reproduction, should not natural selection have long since eliminated such a ‘useless’ object? And in cultures where people eat less processed, fibre-rich diets, appendicitis is much rarer than in the West.6 It has also been suggested in the literature that some cases of appendicitis may also be the result of an overly hygienic society, causing an overreaction from the immune system.7 Gall bladders also sometimes become infected, and have to be removed, but no informed medical scientist would suggest that they have no function.

Another line of evidence

We recently came across a further reason, published as long ago as 1980, reinforcing the conviction that the ‘useless appendix’ argument should have been long gone from the evolutionary repertoire. A study in a reputable journal compared the anatomy in the region of the appendix between various groups of monkeys and great apes.8

Students are often shown the huge caecum/appendix of the rabbit, compared with our own diminutive organ, to try to demonstrate that our appendix is the result of a progressive degeneration. But we are supposed to have had a much more recent common ancestor with other primates (monkeys and great apes) than with rabbits. So does the pattern of the appendix in primates, assuming that evolution has happened, fit the idea that it has ‘devolved’ or degenerated?

The evidence presented in this paper indicates that the answer is ‘no’. Assuming evolution to be true, as the authors do, it fits more readily with the opposite idea—that the appendix has gradually and progressively developed to the ‘fully developed organ’9 seen in humans and gorilla. And that it therefore ‘should not be regarded, in the anthropoid apes and man, as a purely degenerative structure’.10,11

Published: 6 August 2008


  1. Glover, J.W., The human vermiform appendix: A general surgeon’s reflections, Journal of Creation 3(1):31–38, 1988. Return to text.
  2. Maas, F., Immune functions of the vermiform appendix; in: Walsh, R.E. (Ed.), Proceedings of the Third International Conference on Creationism, Creation Science Fellowship, Pittsburgh, PA, pp. 335–342, 1994. Return to text.
  3. Bergman, J. and Howe, G., ‘Vestigial Organs’ are Fully Functional, Creation Research Society, Terre Haute, IN, pp. 43–44, 1990. Return to text.
  4. Ham, K. and Wieland, C., Your appendix it’s there for a reason, Creation 20(1):41–42, 1997. Return to text.
  5. Bollinger, R.R., Barbas, A.S., Bush, E.L., Lin, S.S. and Parker, W., Biofilms in the large bowel suggest an apparent function of the human vermiform appendix, J. Theor. Biol. 249(4):826–831, 2007. Return to text.
  6. Ham and Wieland, ref. 4, p. 42. Return to text.
  7. The paper is referenced in Doyle, S., Appendix: a bacterial safe house , 17 October 2007. Return to text.
  8. Scott, G.B., The primate caecum and appendix vermiformis: a comparative study, J. Anat. 131(3):549–563, 1980 Return to text.
  9. Ref. 8, p. 562. Return to text.
  10. Ref. 8, p. 562. Note that the authors said (in 1980) that this was despite the function of the appendix being ‘obscure’. In the years since, the organ’s likely function has become somewhat clearer. Return to text.
  11. The word ‘purely’ seems a sop to evolutionary tradition, since the evidence they present does not suggest any degeneration, but rather a development, if anything. Return to text.