Why do we have eyebrows?

Judging from the time and money spent on preening eyebrows, they definitely play an important role in our culture in terms of beauty. We pluck, pierce or apply color to our eyebrows to make fashion statements. We also use them in nonverbal communication by simply raising or lowering them. However, they don't seem to serve any physiological function -- or do they?

The answer is yes, though their purpose has lost significance over time as humans evolved. It’s likely that eyebrows played an important survival function for the primitive man who had to escape from predators.

Eyebrows have been described as umbrellas for the eyes. The arched shape helps keep vision clear by diverting rain and sweat away from the eyes to the sides of the face. Sweat is salty and can cause irritation and burning to the eyes -- another reason to divert the moisture.

Whether dodging raindrops or perspiration resulting from a fast and quick escape from a predator, eyebrows helped primitive man in the game of survival. And even though modern-day humans don't rely on eyebrows for survival, they still serve the same purpose of keeping moisture out of our eyes.

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Learn more about the purpose of eyebrows from HowStuffWorks.com.