If you’ve ever noticed a small mark or tiny hole near someone’s ear and assumed it was caused by an injury, it’s actually something quite different. This feature is a genetic trait rather than a scar, and it can reveal interesting details about human development.

Researcher Neil Shubin discusses this in his book Your Inner Fish, suggesting that such traits may be linked to human evolution. He explains that humans share distant biological connections with fish, and this small mark might be a leftover sign from that ancient relationship.

Only a small percentage of people have this feature. It usually appears near where the ear connects to the head and forms early during fetal development. Most individuals who have it may not even notice it unless it becomes pointed out.

This condition is called a preauricular sinus. It is harmless, not a disease, and does not affect overall health. Instead, it is simply a natural variation in human anatomy that reflects the complexity of our biological history.

Interestingly, its occurrence varies by region, being more common in parts of Africa and Asia and much rarer in places like the United Kingdom and the United States. Some theories suggest it could be a remnant of ancient gill-like structures, although this idea remains unproven.