Are there identical fingerprints? At your fingertips. Why papillary patterns are needed Iris

People have long paid attention to skin patterns on their fingertips and even learned how to use them to identify a person, because for each person they are peculiar and unique. Forensic science uses this feature as a way to achieve the goal of proving the guilt of a suspect by taking fingerprints at the crime scene and comparing them with samples in the database or a potential criminal.

Identification procedure

The pattern on the fingertips is formed during the prenatal development of the fetus. The skin consists of several layers, which, connecting with each other, form folds - papillary patterns.

Like everything in the human body, this pattern is determined at the DNA level. There are so many possible combinations of grooves and curls in the print that the probability of matching such a pattern in two people is close to zero. Moreover, the fingerprints are different even for one person on different fingers.

For all its persuasiveness, the theory of the uniqueness of fingerprints cannot be fully proven. Despite the fact that bases with millions of prints have been created, it is physically impossible to remove and save this pattern from every inhabitant of the planet, as well as to compare the prints of living people with those who died long ago. Therefore, the theory remains a theory, although it has found wide practical application.

The fact that the patterns on the fingers are unique, people assumed thousands of years ago, but this issue aroused real public interest in 1877, when the Englishman William Herschel suggested that the papillary pattern of our fingers remains unchanged throughout a person’s life. Many researchers, and especially criminologists, asked themselves the question: "Isn't a fingerprint a unique identifier for each person?" This would open up completely new possibilities in the criminal investigation and would make it possible to keep an unmistakable record of persons suspected of committing a crime. But before this idea could become a reality, it was necessary to develop a classification system for papillary patterns and, most importantly, to prove that the papillary pattern of each person is unique. And if the experts coped with the first task rather quickly, then the proof of the uniqueness of fingerprints still raises questions from many experts.

The human palms are made up of two layers of skin: the cutis, the bottom layer, and the epidermis, the top layer. These layers do not adhere tightly to each other, so over time, folds appear on the cutis, from which our unique papillary patterns are formed. This happens around the seventh month of the fetus's life, so a person is born already with unique fingerprints. As the child grows older, the print increases, but the pattern remains the same. How did the researchers prove that each fingerprint is unique? Actually… not at all. Simply because it's impossible. This assumption was made on the basis of the examinations and analysis of fingerprint databases, among which it was not possible to find matching ones. However, it is not yet possible to take fingerprints from all 7 billion people inhabiting the planet and analyze their fingerprints. And if all the people who have lived on the planet throughout history, then the task becomes completely impossible.

Fingerprinting recognizes that it is still possible to re-draw on the fingertips. It all depends on the probability of this event. Most likely, a complete match of papillary patterns can happen no more than in one case in 64 billion. And if we take into account that, according to rough estimates, about 107 billion people were born on Earth in the entire history of its existence, then, for sure, two people, even if they lived in different eras, had the same fingerprints.

Interesting Fingerprint Facts:

- The Argentinean police were the first to use the Galton method in determining fingerprints.

– Juan Vucetih, a member of the Argentine police, was the first police officer to catch a criminal using fingerprinting. It turned out to be a woman who killed her own sons. After their deaths, she cut her throat to avoid being found guilty. However, after killing the boys, she left fingerprints on the door, so she could not escape punishment.

“Of all the types of forensic examinations, fingerprints are the most evidentiary evidence found at a crime scene.

- The pattern on the soles and toes is also individual for each person. Often it helps to find a person as well as the drawing of fingers.

- It is fingerprints that can show that a person has used drugs - the skin secretes fat, which includes the remains of any substances in the body.

- Your cat will not be able to escape responsibility either - after all, the imprint of his nose is also individual.

Illustration: depositphotos | JohanSwanepoel

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Identification procedure

The pattern on the fingertips is formed during the prenatal development of the fetus. The skin consists of several layers, which, connecting with each other, form folds - papillary patterns.

The existence of twins is an amazing phenomenon, which is not so rare these days. If you look at the situation from the outside, then their appearance in this world can be compared with the plot of a good science fiction novel. The twins themselves, as a rule, do not immediately manage to come to terms with the idea of the presence of an identical double nearby. In this article, we will tell you little-known and amazing facts about twins.

Identical twins have different fingerprints

The term "identical twins" should be taken literally. They are called so because they are practically indistinguishable from each other. But even the most similar twins will have different fingerprints. This feature is strictly individual.

According to experts, their shape depends on the position of the fetus and the density of the amniotic fluid, which spirally wraps around the fingers at different times. Identical twins occupy different parts in the womb, so their hands are pressed to different places.

Fingerprint testing is the only reliable way to tell one twin from the other.

Sometimes one twin disappears

One of the creepiest things that can happen when a woman is pregnant with twins is Vanishing Twin Syndrome.

First, the mother finds out on an ultrasound that she has twins. A few months later it turns out that one of them died right in the womb.

According to statistics, this happens in 20-30% of cases of multiple pregnancies.

Twins separated at birth often lead odd lives

Sometimes twins are separated at birth. At the same time, they do not even suspect that an almost complete copy of them exists somewhere. Surprisingly, at the same time they begin to lead parallel lives in adulthood.

One example is Paula Bernstein and Elise Shane, who reunited at the age of 30. They were surprised to find that both became writers, had the same political views and passions in art. In adolescence, they suffered from identical intestinal disorders, in addition, they edited school newspapers, and studied cinema in college.

Twins begin to communicate even before birth

The womb is very similar to your first apartment outside of school. It's cramped, dirty, and you spend way too much time sucking weird drinks out of an even weirder pipe.

But this first apartment is completely yours, and it's brand new to you, so you dig it. The only thing that can make it even better is a cool, friendly roommate, which is exactly what the twins have.

Twins have an unusually strong bond with each other. According to recent research, they begin to communicate and feel sympathy for each other even in the womb.

For example, it was possible to establish that already at the 14th week of pregnancy, the twins begin to extend their hand to their brother. By the 18th week, they are already regularly touching their partner. At the same time, they are careful when touching the twin's eyes so as not to injure.

"Mirror Twins"

"Mirror twins" have quite a lot of differences compared to the more common identical twins.

In fact, they look exactly the same, but their functions are mirrored. They all have the same genes, but one twin can be left-handed and the other right-handed.

If one has a noticeable birthmark on the left leg, then the "mirror twin" will have a birthmark in the same place, but on the right leg. Often they have bite on opposite sides. At the same time, despite this strange asymmetry, most often, they are monozygotic.

The mind of Siamese twins can be connected

Tatiana and Krista Hogan are twins whose skulls are fused together. The fact that they are alive is already a miracle. Most of these phenomena require surgical separation in order to survive.

Even more incredible is that there is a physical connection between their brains, which neurosurgeons call the thalamic bridge. Thanks to this, they can even feel each other on a sensual level. For example, if Krista tries some new food, Tatiana tastes it.

Twins can have different fathers

It's hard to say where this strange fact would be more appropriate: in a science fiction novel or a sitcom. It is now reliably known that twins can have different fathers.

The fact is that twins appear when a woman produces two eggs, each of which is fertilized by a separate sperm. Therefore, if she meets in the same period with two men, this is quite likely.

Such situations most often occur in animals, but they also occur among people. There are at least a few proven cases.

Gemini communicate in their own language

This phenomenon is observed in 40% of twins. It's called cryptophasia. When twins are still very young, just beginning to master speech, then, unlike most children, together with their partner they are able to create a language that no one else will understand except them.

These autonomous languages tend to disappear when toddlers learn adult language. But this doesn't always happen.

Matthew and Michael Youlden are two adult twins who have not lost the language they spoke as children. From about the age of 7, they began to actively develop it. They had their own alphabet, grammatical rules, it became possible to fully communicate on it.

They call their personal language Umeri. This is an amazing phenomenon. Interestingly, the twins keep it a secret from the rest of the world.

The twin gene is passed down from mothers

Counts. that a woman's ability to produce two eggs instead of one. transmitted genetically. So if you didn’t have twins in your family line for several generations, it’s unlikely that you will have them either.

The birth of twins is always directly related to ovulation. Years of research have concluded that the genetic predisposition is transmitted only from woman to woman.

There are more and more twins

In 2014, it was found that a record number of twins were born in the world. Since 1980, the frequency with which they were born has increased by 76%.

Basically, this is due to the fact that modern women give birth all at a later age.