Have you ever noticed the groove between your nose and your top lip? No? Or else noticed, but don't know what is it for actually! The horizontal groove is known as Philtrum and is a vestigial part in humans. Most of the mammals have this philtrum and is very helpful to them. This philtrum is used to wet their noses and help them to smell well.
It is a vestigial part in human beings but does a better job in defining the facial features. Let's talk about twins, how will you differ the identical twins? Most of the time we don't identify tehm correctly just because of same features of face. But this little groove is helpful in identfying them better. During first trimester of pregnancy, face evolution is the very first step. The attatched video will get you know the idea, how a human face is evolved. This feature starts from the embroyo of rice grain size to the kidney bean size. It almost takes a time period of 12-15 weeks.
Actually the lip defination differs just because of this philtrum. If we don't get a proper philtrum during early stage of our life, it may result to the "fetal alcohol syndrome" and it will result in flat top lip. But if it fails, then "cleft lip" may result.
See, how from the size of a grain to a kidney bean our face creation takes place in the early stage of life. This happens in the first trimester of pregnancy.
The groove between our nose and the top lip add a beautiful feature to our faces. It's good to have a proper lip finishing.
Due to flat philtrum, it results in thin upper lip.
We humans have evolved from fishes. This fish also has the groove between its nose and lips!
Imagine if we don't have philtrum, we would look like as Lord Voldemort. This would be weird to imagine but hopefully true!
Almost every mammal has got the philtrum. This helps them to smell better and fast.
Yes, they too have philtrum.
Most of our cartoon characters don't have a philtrum. Would we look like them if we too don't have it?
This is due to the failure of the philtrum.