There is a word in German that refers to couples: identical. Of course, on some occasions you’ve seen someone who looks reasonably like someone you know, on the street, on the subway, or in a cafeteria. So much so that you thought it was him and even went to talk to them and quickly realized that they were not who you thought they were. The human population is estimated at 7.9 billion, and with so many possibilities, it is very likely that these kinship repeats occur randomly.

But how likely is it that someone is like us? Scientists believe that someone who is 100% the same as one of us is difficult, but someone who is 75% or 80% the same is probably already around because there are so many people in the world and that’s why we’re close. Number of DNA fragments.

Where is my twin? Photos of people who are almost the same physically but are not genetically related are a phenomenon that excites users on the Internet. And social networks have led to just that, for people to share and exchange images of very similar people. Actually, François Brunelle is a Canadian artist who has been photographing like-minded people around the world since 1999. One of these comparisons was the comparison of Ferrari’s founder, Italian Enzo Ferrari, and German football player Mesut Özil.

The world is full of similar cases, and science has finally studied why this happened and what the consequences were.

Study. Published in the journal Cell Reports, the team led by Manel Esteller of the Josep Carreras Leukemia Research Institute set out to discover why there are people who have the same face but are unrelated. Researchers contacted stunt photographer Brunelle and found 32 volunteer couples. Photographs of their faces were analyzed with three people. software face recognition. The similarity detected in the twins reached 90%-100%.

However, the number of couples matched with at least two programs was very high in the analyzed photographs of strangers who did not know each other at all (75% similarity in 25 out of 32). And in half of the pairs, the three programs found correlations, so 16 were extremely similar.

Almost same. The results revealed that the shared genes fell into several categories: on the one hand, genes associated with the shape of the eyes, lips, mouth, nostrils, and other parts of the face; genes involved in bone formation in relation to the shape of the skull; genes located in different skin tissues; or genes related to fluid retention that differentiate the volumes of our face. Also, most of these 16 couples had similar height and weight, among other biometric factors.

Why? Why? To answer the question of why this phenomenon occurs, scientists examined biological material, the genome, and two other components: the epigenome, which is like the chemical markers that control DNA, and also the microbiome, which is a type of virus and bacteria. The Genome we had, genetics matched these people, while epigenetics and the microbiome (more related aspects of the environment) drove them away.

What emerges from the study is that the most important thing in these cases is that the couples have similar genetics, a similar DNA sequence, and that the similarity is not due to shared families. There is no relationship between them, but sometimes the same regions or DNA sequences of these people can be created, as this can happen by chance.

Not only looks, but also personality.. Another interesting fact is that the volunteers not only share physical traits but also behavioral traits. They were asked to fill out a questionnaire containing more than 60 questions about their living habits, and in some cases there were similarities. The correlation between behavioral characteristics such as smoking and education level suggests that shared genetic diversity may also affect habits and personality.

Useful for disease detection or forensic science. The researchers believe these analyzes could be vital in biomedicine applications. Identified genes and their variants, which are mainly important in determining the shape of the face and thus the nose, mouth, forehead, ears, may also be involved in the pathologies. In other words, that person’s genome can be partially extracted from a face so that genetic diseases can be screened.

Also, molecular basis can be used in forensics. For example, it could be used to create a system in which the face of an unidentified criminal or victim is reconstructed from his DNA.

Picture: François Brunelle