When Thomas Jennings tried in 1910fleeing the scene of the murder, he was “lucky” to become the first person in history who was caught thanks to his fingerprints on the drying railing near the house. Since then, fingerprinting, which is a way of identifying a person thanks to the unique pattern on the skin, actively continues to appear as the most important evidence in judicial investigations. But, it is obvious that fingerprints do not exist for the sake of entering into the general police database. So why does a person have papillary patterns on the skin of his hands and what biological role do they play? Let's try to figure this out in this article.
Why does a person have patterns on the fingers?
In the process of studying the papillary pattern onskin, experts adhered to two theories about their biological purpose. So, a pattern on the fingers of a person’s hands may be needed to improve adhesion to any surface, as well as to enhance sensory perception. For a long time, the dominant theory was the creation of better grip due to tiny depressions and elevations on the fingers, as modern automobile tires are similarly arranged. In order to test this hypothesis, scientists conducted a laboratory experiment to identify the functional similarities of the patterns of the fingers with the principle of operation of car tires.
According to an article published on the portalLivescience.com, during the experiment, experts dragged a special plate of organic glass through the fingertips, while changing the pressure force. As it turned out later, the actual contact area was reduced compared to smooth skin, which can serve as a refutation of the theory of creating additional adhesion.
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Our fingers are known to have four typesmechanoreceptors or cells that respond to mechanical stimulation and touch. In order to confirm or refute the theory of an increase in sensory abilities, scientists have studied in detail Pacini bodies, which are found at a distance of about 2 millimeters at the fingertips and are responsible for the perception of fine textures and light vibrations.
See also: Neural network learned to fake fingerprints
For the next experiment, scientistsconstructed a biomimetric tactile sensor that is able to detect vibrations, similar to Pacini's human bodies. One version of the device was created with a smooth structure, and the second had a relief surface similar to a human finger. In addition, the ribbed surface amplified the frequency of oscillations, to which Pacini bodies are very sensitive. Scientists suggest that fingerprints enhance point vibrations and direct them to sensors under the skin, enhancing fine, detailed sensory information about the surface. The conducted experience served as an additional factor to confirm the assumptions about their biological function in nature.
Scientists suggest that the capture processany item is also associated with our prints. Due to its specific pattern on the fingers, we are able not only to hold the object in our hands, but also to feel the degree of fixation of the object in order to strengthen the grip in case of slipping if necessary.