Physical doppelgangers also have genetic similarities

Have you ever encountered this confusing encounter? A stranger on the street looks just like you, your twin. Our appearance Physique Both are dictated Genetics and our environment. There are many possibilities, sometimes two unrelated people It looks like two drops of water. This is precisely what Spanish scientists are interested in Subsidiaries Among several research institutes in Barcelona. How similar are two people who look alike, not physically, but genetically? The results of this intriguing study are out Cell reports.

Physical appearance, genetic appearance

Finding a pair of looks is not an easy task, but Spanish researchers were able to rely on the work of Canadian photographer Francois Brunel, who has dedicated his life to research. Similarities between humans. Since 1999, he has been collecting photographs of people who don’t know each other — and are unrelated — but have the same face. In this gallery of identical looks, 32 couples agreed to participate in this scientific study. Their photograph, taken in black and white by François Brunelle, was analyzed by the trio Software Different facial recognition systems. In addition, they answered a questionnaire about their lifestyle and provided saliva samples for genetic analysis.

The three software programs compared 27 physical characteristics of the faces of the members of each pair: location Eyebrowsinterval Eyes For example the height of the upper lip. Half of the couples were recognized as very similar by the three software; Genetic analysis was performed on these 16 pairs of genes.

The latter yielded fascinating results: 9 pairs of looks were qualified by scientists as “ultra-lookalikes” because they shared a disturbing genetic similarity along with their phenotypic similarity (physical appearance). In fact, in this extreme case, approximately 19,000 nucleotides located in 3,700 different genes are shared simultaneously between two individuals.

To take the like-for-like comparison a step further, the scientists also compared genes, epigenetics, and factors that don’t concern epigenetics. microorganism. Methylation patternsAtn — one of the possible epigenetic changes — is present only in an identical pair. In contrast, ultra-lookalikes share many epigenetic similarities. The same trend is observed for microbes. Surprisingly, people who look alike share certain lifestyle habits despite not knowing each other, suggesting that genes somehow influence our behavior.

This study suffers from several limitations, the number of origins analyzed is modest, so interpretation of the results should be taken with a grain of salt. Look-same pairs were created from two-dimensional black-and-white photographs, which masked physical properties such as contrasts. Color skin. Finally, the participants were predominantly of European descent, and therefore, the results cannot be interpreted beyond this framework.