As a guy who has one eyebrow slightly higher than the other, I am perhaps more aware of eyebrows on others as you symmetrical faced folks.  And let me tell you, there are some "unusual" eyebrow approaches and treatments out there.

But science says our ancestors were all well aware of eyebrows at the earliest stages in the development of communication. This could raise an eyebrow - Scientists have discovered that eyebrows were the key to how early humans began communicating with one another.

More than that, researchers say that eyebrows were also extremely important because they made it possible for humans to work together. Who knew?

One conclusion study authors have drawn is that the eyebrow is the missing link in putting together the puzzle of how modern humans managed to get along so much better with each other than other now-extinct ape-like creatures. (Telegraph)