What you learned in school
Medical textbooks described the appendix as a classic "vestigial organ" - a useless evolutionary leftover from herbivorous ancestors who needed help digesting plant matter. Students learned it was like the tailbone, a remnant with no current purpose whose only significance was causing appendicitis. Medical schools taught that it was an evolutionary relic that served no function in modern humans and could be safely removed without consequence.
What we know now
Medical textbooks described the appendix as a vestigial organ - a useless evolutionary leftover from our herbivorous ancestors. Students learned it was like the tailbone, a remnant with no current purpose. The only time it was mentioned was in the context of appendicitis. Research has now shown that the appendix serves as a reservoir for beneficial gut bacteria. It helps recolonize the intestines with good bacteria after illness or antibiotic treatment. It's part of the immune system and may play a role in developing immune responses. The "useless organ" narrative has been completely overturned.