Almost every body part serves a distinct function, be it the nose or ankle or eyebrows. But, Have you ever thought about the groove between your lips and nose? The groove on your top lip that lies just beneath your nose is called a philtrum. It has no obvious function but instead it is an accident of our origins, it is a clue to our fishy past and how our faces first formed.
This video by BBC further tells you about its origin and also explains the way our unique faces have developed through history.