Fang, appendix and third eyelid: what are atavisms and why do we need them today

Canine tooth, appendix and third eyelid: what are atavisms and why do we need them today

Man is the self-proclaimed pinnacle of the evolutionary process (at least for now). Our bodies are the result of development and improvement over millions of years. We no longer need gills, claws, huge fangs and fur to survive, but nature still left reminders of the cruel times of natural selection. Their name is rudiments and atavisms. (Let's add that tourists, as a subspecies of Homo sapiens, have their own unique rudiments: some still travel with paper maps and use phrase books).

The legacy of distant ancestors

Now we are less ape than early Homo, but the rudiments remind us of our origins. Coccyx – these are fused vertebrae, the rudiment of the tail; hairline – all that is left of the wool, which reliably protected from the cold; appendix– the legacy of artiodactyls that ate coarse plant foods. However, the list of rudimentary organs is not limited to this “school” set. The so-called goosebumps from strong sensations or from cold causes the effect of piloerection: special muscles raise the hairs. In cats, at the moment of aggression, exactly the same thing is observed – the hair stands on end.

We no longer need to recognize a potential partner by smell – there are plenty of other ways, but vomeronasal organ , which catches pheromones, is still present in the olfactory system. True, for the majority it is poorly developed or does not work at all (but not for everyone). Wisdom teeth and fangsalso long since lost their function. Once they were required for grinding cartilage, bones, tough branches, raw meat. Today, someone's wisdom teeth do not even grow, and the fangs are very small. Among your acquaintances, you will surely find at least a couple who can move their ears. ear muscles work well for them. Now a vestige, they were once responsible for fine and directional hearing, helping our ancestors to hunt and hide from predators.

Remains of the third centurywe got from lizards and other reptiles. This translucent film, which protects the sclera from drying out, has been reduced in the course of evolution to a small triangle in the corner of the eye.


Atavisms occur in people due to deviations at the gene level. In a normal situation, there should not be such anomalies, but sometimes a person suddenly shows a sign characteristic of his distant ancestors. This is extremely rare.

Science knows cases of the birth of children with a full-fledged tail: at some point, its development in the womb did not stop, like in the vast majority of embryos. There are also people with excess hair that resembles wool: hair grows thickly everywhere, not even on the cheeks and forehead. The last atavism described in detail is extra pairs of nipples. Occasionally, there are even additional mammary glands that can secrete milk.

Remnants of the past

With atavisms, everything is more or less clear – this is a system failure. Why do we need rudiments and why can't we get rid of them? Perhaps in the distant future we will get rid of them, but for now they remain an important part of the body. Wisdom teeth, for example, still help to chew food better, but if they are not there, nothing terrible will happen. Fangs, too, in case of caries, need to be saved to the last – and the point here is not only in aesthetics, but in usefulness. In Japan, for example, they even consider a protruding fang to be very sexy. Finally, the appendix is ​​an important part of the immune system. Its removal in early childhood (and they tried to practice this with the best of intentions) can significantly undermine the body's defenses, and in adulthood it can provoke problems with the intestines.

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *