Scientists have refuted the theory of the uselessness of the appendix Appendix, once considered a harmful body, is rehabilitated. After the opening of its important role in the immune system, it turned out that the appendix also had a rich evolutionary history: according to American biologists, it arose 80 million years ago. A few decades ago, the appendix, or the cecum, was considered a rudimentary, that is, the body that lost their appointment during evolution.