Why do we have fingerprints?

Author: Layal Bou Abdo MNS

Illustration: Angeline Boswell

Let’s solve this riddle first!

What’s something that you always have with you and that you always leave behind?

The answer is… your fingerprints

What are fingerprints?

Have you ever looked at your fingertips? Did you ever notice that they’re covered in little bumps and ridges? If you did not notice them yet, grab your magnifying glass or go under the sunlight. Now, look at those patterns on the tips of your fingers. Those are your fingerprints or what scientists call dermatoglyphs. Dermatoglyphs are special parts of your body and your unique identifier.

Shapes of our fingerprints

Scientists have found that there are 3 patterns in fingerprints:

–    Whorls, like a swirl or circles

–    Loops, like curvy lines that start and end on the same side of the finger.

–    Arches, which start and end on each side of the fingers

Each of your fingers has a different pattern and usually, you will have 2 or 3 patterns of fingerprints. Moreover, it is very rare to have only one type of pattern.

Nobody else has a fingerprint that is like yours. Your fingerprints are different from any other person. When you get bigger, your fingerprints get bigger and the pattern never changes. Your fingerprints are unique to you only they are your biological identity. In short, fingerprints are the ID that nature has given you.

How do fingerprints form?

The fingerprints patterns are controlled by genetics. Even though many people think it’s random, a lot of it is a product of your genes!

The ridges are formed before you are born when you were in your mommy womb! They are one of the earliest features to develop inside the womb.

Between the 6-7 weeks of the fetus’s development, the fetus starts to get some thick pads on his palms and feet. Those pads are called Volar Pads. Volvar Pads appear when special kind STEM cells (cells that can produce a different kind of cells) swell beneath the existing layers of the skin.

On week 9-10, the pads stop growing while the hands continue to grow. On week 15, the volar pads smooth out in the hands and feet that we know.

Whether the volar pad is big or small, or off to the side or grows unevenly, determines the main pattern of a fingerprint.

Because your volar pad size and orientation is genetic, many relatives and most of the identical twins have the same main pattern on each finger. So, DNA alone isn’t from where the uniqueness of the fingerprints comes from. Instead, it’s the result of the chaotic way in which your fingers grow. The form of the ridges is also influenced by environmental factors such as:

• The fluids pressure changes inside the womb
• The position of the fetus inside the womb, weather touching the amniotic sac
• The density of the amniotic fluid slushing around the fetus inside the womb.
• How nerves and capillary grow in the layers below the skin
• The direction to which the finger orientated relative to gravity

Last, the pattern locks in during the 24 weeks of development of the fetus. Furthermore, it never changes throughout your life.

Why do we need fingerprints?

We all know by now that fingerprints are a form of Identification and Uniqueness. The fact that everyone has a different fingerprint can also be useful. In particular, the police can use fingerprints to solve crimes. If a thief stole jewellery from a store and left his fingerprints behind, the police can check those fingerprints. They compare them to their database to find who has a matching fingerprint.

Can I live without fingerprints?

Scientists have found that fingerprints are very important in the mechanism of touch. Without them, it’d be difficult for you to read information and interact with whatever you’re touching or holding in your hands.

Having no fingerprints is like wearing leather or medical gloves!

Try the below activities out at home while wearing gloves! What do you notice?

• Did you find difficulties in scrolling up or down on your phone or unlocking your laptop or tablet?
• How about feeling? Do you feel your fingers interacting with the buttons of the computer for example? Try to take a pinch salt, Oops! This was way more than a pinch!
• Do you feel the temperature correctly?
• How about sensitivity? Are you able to figure out how different materials feel like (smooth, rustle, soft) or the texture of fabrics?

There is a small minority of people who are born with smooth fingers or voided prints! This condition is called Adermatoglyphia, a rare genetic disorder, in the chromosomes. That causes a person to have no fingerprints. There are only four families in the world that do not have fingerprints.

Those people often experience unpleasant side effects, including skin blistering. That’s because the pattern ridge structure at the surface of your fingers does not allow fluid to accumulate. Thus, reduces the risk of blisters.

In Canada, currently in Manitoba, there is one family with adermatoglyphia. All are females, not males.

If you do not have fingerprints you will face difficulties in obtaining a passport or travel outside the borders of your country.

Let’s talk some history

Humanity has known about the importance of fingerprints for a very long-time.

In Ancient Babylon, about 2000 years BC people left prints on clay tablets as a signature. In 220 years, BC the ancient Chinese used fingerprints to sign legal documents. Though, they did not realize how unique these marks were. In 1684, an English physician published the first scientifical analysis on the ridges that appear on the palm and fingers. In 1788, a German analyst, Johann Mayer, declared that no two people have the same pattern.  But it wasn’t until 1902 in the UK that the science of fingerprint would play an essential role in a criminal investigation for the very first time.

Fun Facts! Did you know?

We are certain your kid asks you health (human & animal) questions that genuinely leave you stumped! Leave a comment below and we are happy to answer “why” in future blogs.

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