Why Do We Have Fingerprints?  

Introduction 

     I've always wondered how fingerprints formed on our hands and why humans even have fingerprints. If you are also interested in learning more about fingerprints, sit down with me and I'll help you through my website to explore the mysterious world of fingerprints! 

How Fingerprints Are Helpful

     Humans start connecting with their parents from when they are first born by holding hands and using their sense of touch. Also fingerprints help the human body, by picking up and grabbing objects.

      The patterns on our fingers are very important to controlling fine motor skills, like being able to hold a pencil to write. Fingerprints are important to the sense of touch. Without them, you wouldn't be able to sense what objects feel like.

Grabbing and Holding

     People used to believe the fingerprints helped to increase friction so that you could grip and hold things better. But scientists have done experiments that have actually shown that the opposite is true. 

     Fingerprints actually reduce friction, because all of the grooves and ridges in your fingerprints cause your skin to touch objects in fewer places, which reduces friction.

    However, fingerprints may help humans improve their grip in other ways than friction by allowing human skin to stretch more easily, and by helping to drain water and wetness from your skin so your fingers don't become slippery.

The Layers of Skin

     Humans have multiple layers of skin. The outermost layer of skin is called the epidermis.

    You can see patterns such as arches and loops only on your outermost layer of skin. Old skin cells are constantly being replaced by new skin cells.

    The basal cell layer is the deepest layer of the epidermis. The basal cell layer is the place where new skin cells are made. The basal cells constantly divide and multiply, and this pushes the older cells up toward the surface of your skin.  The basal cell layer of skin grows faster than the epidermis (outer layer of skin) and the dermis (middle layer of skin).

The Patterns

     Fingerprints are just patterns that form on our fingertips. There are thousands and thousands of theories about fingerprints and why they are so unique, and not even scientists are exactly sure.

     Fingerprints come in unique patterns and shapes of arches, loops, and whorls. Each human has a unique and different set of fingerprints. Even identical twins that appear exactly the same have different fingerprints! This is helpful to identify people.

    Did you know fingerprints show up in more places than just your fingers? We also have patterns on our palms, toes, and feet, and just like fingerprints, the skin on these other places forms into a unique pattern.

Uniqueness of Fingerprints

     The patterns on our fingertips cannot be identical to someone else because the shapes and patterns form in a unique way for all people. Your DNA can generally affect the shapes of your fingerprints, so identical twins with identical DNA, may have similar fingerprints.

          But even identical twins will have different fingerprints because the shape and patterns are not only determined by DNA. Environmental factors also affect the shape and patterns of your fingerprints, and since these environmental factors will not be exactly the same for any two people, the fingerprints will also not be exactly the same. 

Why Humans Have Fingerprints

    So after all of this, what exactly causes humans to have fingerprints? Why don't humans just have flat, smooth skin?

    Well, first you need to know this fun fact: before a human is born, it is called a fetus. While the fetus is inside the mother's body, your fingerprints are being formed.

     The layers of your skin don't grow at the same exact speed. The basal cell layer grows faster than the outer layers of the skin. This causes the outer layers to fold and form a variety of unique patterns. And this is what makes fingerprints!