History Main / WeWillNotHaveAppendixesInTheFuture

** ''Literature/PebbleInTheSky'': [[SpaceRomans Imperial officials]] realize Joseph Schwartz is a time traveler by the fact he has wisdom teeth and an unusually large appendix. {{Justified|Trope}} by [[spoiler:the future Earth being covered in radiation after a nuclear war]], which would increase mutation rates vastly. How much time passed between the "present" and the "future" is disputed by the fanbase due to inconsistencies within the series (One character estimates between fifty thousand to a hundred thousand years since humanity only existed on a single planet, even assuming that humans didn't evolve simultaneously on multiple planets.)

* ''The Man Who Awoke'', published in 1933 on ''Wonder Stories'', is a series about Norman Winters, who invents a technology for suspended animation and visits [[ToTheFutureAndBeyond successively more distant futures]]. By the year 5,000 humans have lost the appendix, followed by teeth in the year 15,000 and tonsils in 25,000.

* Some people don't grow wisdom teeth. [[InvertedTrope On the opposite end]], some people have them but don't need to get them pulled, either because they're quite fine staying put in the jaw, or very fortunately erupt and have the space to do so without getting impacted or infected.

* This trope was facetiously employed in ''Series/PhilOfTheFuture'' when Phil ran into a problem: he would have to be seen barefoot to stamp tomatoes in a farm on a class trip, but in his time, no one has pinky toes. To quote Phil's mother [[SciFiWritersHaveNoSenseOfScale "They won't lose their pinky toes for another 70 years."]] Ironically, pinky toes are actually used for balance.

* The tiny arms of ''UsefulNotes/TyrannosaurusRex'' and other theropod dinosaurs are believed to have been the result of this. Some paleontologists speculate that if the Cretaceous-Paleogene extinction hadn't happened, the theropods would have lost their arms entirely tens of millions of years later.

* ''Literature/TheWarOfTheWorlds1898'': In designing the {{Martians}}, Creator/HGWells started from a humanoid body plan, then stripped off ''everything'' -- limbs, digestive tracts, sexual reproduction -- that he thought mechanization and/or medical technology could potentially make obsolete. All that he left them was a giant head, a few tendrils for pushing buttons, and the ability to breathe. Instead of eating, they drain captured aliens and humans of blood and inject it into their bodies.

* If the occurrence of the appendix among humans decreased until only a testimonial number of people had it, it would become what in Biology is known as Atavism. Horses with lateral toes and whales with leg bones are among the best known examples.

* Loss of eyes is a frequent phenomenon among cave-adapted and some burrowing animals, as vision is useless in a lightless environment. In this case, the loss serves a practical purpose, as eyes are a vulnerable point for injury or infection, so become a useless liability if they can no longer collect sensory input.