Our footprints are an evolutionary adaptation that has made it possible for us to manipulate tools, climb, or touch more effectively. Thanks to them, everyday actions such as unlocking your phone or opening a jar are much easier.
By Juan Carlos Álvarez
United Kingdom, November 23 (The Conversation).- If you carefully examine the tips of your fingers, You will see a network of curves, spirals and branches. They are called papillary ridges and they allow, together with the grooves between them and the secretions of our skin (sweat and grease), to form a “drawing” or fingerprint when touching an object.
The development of those papillary ridges occurs in the fetus –between weeks 10 and 16 of gestation– and depends on the interaction between our genes, the growth of skin tissue and the movements, pressures and position of the fetus within the uterus.
This complex process means that not even identical twins have the same fingerprints. Although this is used by the police to solve crimes, in reality they emerged to help us touch, grab and explore what is around us.
Having them gives many advantages
Fingerprints therefore have a basic function: they help us interact with the world. Scientists agree that they fulfill three main functions:
1. Improve grip. Papillary ridges increase friction, just like the treads on a tire or your shoes. Thanks to them we can hold small or slippery objects without them escaping, even with wet hands.
2. Distribute the pressure. When gripping something, the ridges distribute force better and prevent the skin from being easily damaged or worn.
3. Increase tactile sensitivity. Under the ridges there are nerve endings that detect very fine vibrations and textures. The ridges therefore act as “amplifiers” of touch, allowing us to feel with much more precision.
Koalas have fingerprints so similar to human fingerprints that not even the police could tell the difference. 😱👣
🔍 Under the microscope, their fingers show the same arcs, loops and spirals as ours. No other animal, not even the great apes, comes close… pic.twitter.com/eO6eZfJXWM
— Teach me about Science (@EnsedeCiencia) October 17, 2025
In other words, our footprints are an evolutionary adaptation that has made it possible for us to manipulate tools, climb, or touch more effectively. Thanks to them, everyday actions such as unlocking your phone or opening a jar are much easier.
But, in addition, the papillary ridges have another mission: to channel sweat. At the top of many ridges the pores of the eccrine sweat glands open, releasing small amounts of water and salts. This not only helps regulate body temperature, but also improves contact with surfaces, increasing friction.
From evolution to the forensic laboratory
Although our fingerprints evolved for these tactile purposes, three properties make them an indispensable tool for human identification:
1. They are unique: each person has a design that has never been repeated so far.
2. They do not change: they remain unchanged throughout life, unless there are very deep wounds.
3. They are perennial: they appear before birth and persist even after death.
Thanks to this, fingerprinting (the science that studies fingerprints, born at the end of the 19th century) has become a fundamental support in criminal investigation.
The #Fingerprint It is a key technique in #HumanIdentification. Its precision and speed make it an invaluable resource for locating missing and unlocated people. pic.twitter.com/ATGpKg0bgG
—Nal Commission. by Search Mx (@Busqueda_MX) November 17, 2025
Born without traces
However, some people are born with completely smooth skin on their fingers. They suffer from a very rare genetic disorder, located in the SMARCAD1 gene, which is called adermatoglyphia. This disorder is so rare that affected families in the world can be counted on the fingers of one hand… even if that hand has no footprints.
In reality, people with adermatoglyphia lead normal lives, but may have more difficulty manipulating objects or regulating sweat in these areas. In their daily lives, they may encounter curious obstacles: from problems in passport control to difficulties in using fingerprint recognition systems on mobile phones.
Much more than a biological “signature”
Now that you know all this, the next time you unlock your phone with your finger or leave your fingerprint on a glass, remember that fingerprints are the result of millions of years of evolution that help you grasp, feel and explore the world with your hands.
After all, each of our footprints whispers a secret to us: we are born unique, we live unique and we leave a unique mark on the world because there was and will not be anyone like you.