In 2017, American Josiah Martin became famous for his incredible resemblance to the main character of the series "Game of Thrones" Jon Snow. A year later, in one of the Russian Instagram accounts, an exact copy of the wife of the English prince Harry Meghan Markle was found. There is no mysticism in such coincidences, scientists assure. There is a perfectly rational explanation for the doubles.
One in a trillion
In 2016, Irish student Niam Jini launched a social media campaign to find her twin. Within a couple of months, she met the American Irene Adams, who looked like her like two drops of water. The DNA test showed that the girls, despite their striking physical resemblance, are not relatives. Their common ancestor lived no later than 20 thousand years ago. Scientists from the University of Adelaide (Australia) analyzed the measurement data of about four thousand faces and identified eight key parameters by which you can determine the degree of similarity of different people. First of all, these are the distances between the eyes, ears and eyebrows, the length of the nose and the width of the mouth. The calculation results showed that the probability that somewhere on Earth lives at least one pair of people who have all eight parameters coincide is 1: 135. However, their chance of meeting is one in a trillion.
Distant similarity
Australian scientists have been pretty tough on the definition of twins. If the distance between the ears differed by only one centimeter, people were not considered to be alike. But the human brain perceives faces differently. According to a study by American neuroscientists, a number of areas of our brain responsible for perception and recognition of faces are activated only if the image of the face appears along with the image of the body. According to scientists, this allows you to correctly interpret facial expressions, eye expressions and the emotional state of a person. Unlike artificial face recognition systems, we are able to identify our acquaintances even from highly distorted images. In an experiment by American researchers, volunteers recognized the faces of celebrities, despite the fact that they were elongated: their width was only a quarter of the original. In other words,the brain perceives the whole image. Therefore, a slight difference in the ratio of similarities will not affect the result in any way - whether people are considered similar or not. As British researchers have found, a person is able to remember an average of about five thousand faces. Individual indicators range from one thousand to ten thousand. And this greatly increases the chances of mistaking a remotely similar person for his double.
Face sculptors
The most important facial features to recognize are the eyes, mouth, nose and eyebrows. However, it is their formation that depends entirely on genes, scientists from the Imperial College in London have found. They compared sets of similar and different traits for identical twins and twins and found that the shape and size of the tip of the nose, the location of the inner corners of the eyes, cheekbones, areas around the mouth and head coverage are determined by genes with almost one hundred percent probability. These data are confirmed by the results of the work of an international group of scientists, who, trying to understand which genes affect the morphology of the face, gave one of the possible explanations for the existence of twins. Experts analyzed the images obtained as a result of magnetic resonance imaging of the volunteers' brains and their photographic portraits,to create a map of "starting points" on the face and to navigate when determining the distance between them. They then used a genome-associated approach to study nearly ten thousand Europeans with independent replicates to find DNA variants involved in facial formation.
Externally similar volunteers were divided into five groups, and it turned out that the facial features that gave the similarity were the result of the work of the same gene variations. If people who are not related, these genes are located at the same locus - a certain place on the chromosome, then they will have the same facial features.
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Alfiya Enikeeva