Doppelgangers are more similar than thought – they have a similar genetic makeup

We have all seen at some point someone who is strikingly similar to another person. But are it only appearances that remind each other, or is there something else that unites them? Although they are unrelated and can live hundreds of miles away.

Using facial recognition algorithms, Spanish researcher Manel Esteler and colleagues at the University of Barcelona, ​​Spain, attempted to answer the question. The short answer is: Yes. It’s so much more than just looks that unite people “like the wearer”.

Our study provides unique insight into people who share the same appearance and we can show that people who look a lot like each other also have a similar genotype, says Manil Esteler in a press release.

Since 1999 Canadian artist François Brunel collected images of the “Double Pedestrians”. That is, people who are very similar in appearance, without being relatives.

Using facial recognition algorithms, Manel Esteler and colleagues selected 32 “pairs of twins” from Brunel’s group. In addition, participants had to answer a series of questions and provide a saliva sample that was analyzed for genetic material, microflora (bacteria) and epigenetic changes. The latter can be described as permanent chemical changes in the genetic material, which can arise from environmental factors.

The finding, now published in the journal Cell Reports, shows that people who look very similar also share a number of genetic variants with each other. Their genetic mass is therefore significantly more similar, compared to two randomly selected individuals.

Regarding epigenetic and microflora changes, the same relationship did not appear, although there were other similarities, such as weight and height as well as presence of smoking and education level.

“You can imagine that these findings could have an impact on forensic investigations, if you had to construct a person’s face based on their genetic material, or in genetic diagnosis, because the face gives clues to what the genetic material looks like,” says Manel Esteller.

Patrick Magnuson He is the director of the Swedish Twin Register, which is operated by the Karolinska Institutet and is the largest registry of its kind in the world. He finds the study “funny,” though he did not fall out of his chair in shock.

We know that identical twins are often too similar to tell them apart. We also know that the reason for this is that they share the entire genome (clones). So it’s not surprising that people who are so similar that they can be taken to identical twins also have a similar genetic mass, as this study clearly shows. The tables were turned, so to speak, he wrote in a comment for DN.

The fact that some of the other characteristics are similar to each other also does not surprise him much.

Since the genes that influence facial design are scattered over the entire genetic mass, it’s also not surprising that other genetically determined characteristics have become more similar among these “pseudo-twins,” he says.

There are restrictions on studying is the small sample. 32 pairs of “looks alike” are not many in genetic contexts. On the other hand, the small number is not unusual, he says, given how rare there is someone who is almost an exact copy of themselves. Luckily.