Here's why:
* Pigment: Red hair is caused by a recessive gene that produces a pigment called pheomelanin. This pigment is less common than the melanin that produces brown and black hair.
* Distribution: Red hair is most common in people of European descent, particularly those with Celtic ancestry. It is less common in other populations.
* Evolution: The exact reasons for red hair's distribution are still being debated, but theories include its connection to vitamin D production in northern latitudes, protection from UV radiation, and its potential role in sexual selection.
So, while red hair is a natural hair color that occurs in some people, it's not the most common or widespread.