What Science Says About Unrelated People Who Are Physically Too Similar
6 min read- Margarita Rodriguez
- BBC News World
Agnes was traveling by train when a man approached her and started talking about topics she had no idea about. The subject soon realized that it “wasn’t what he thought”. And it didn’t take long for him to say he knew him Similar…a similar personwhich is a German term for “double”.
Agnes was encouraged to meet her partner’s girlfriend on the train, and saw Esther via Facebook. Later, they met face to face.
“We did really well right away. It’s not just about our looks, but our personalities are similar.”
For Esther, “It’s so weird and wonderful to see a part of you in someone else.”
But what makes the experience so special is that she and her partner are similar in personality and interests. “We have the same tastes: music, clothes, tattoos.”
When Esther was 32 and Agnes was 28, they applied to François Brunel, who shared the story of the two Dutch women with BBC News Mundo, the BBC’s Spanish service.
The Canadian photographer recalls that when he saw them, he was “extremely excited to see that they looked alike”.
The artist has spent years photographing people, in different parts of the planet, who are not related and very similar.
So, in the photo below, Ester and Agnes photos in 2015.
Agnes and Ester are just two of hundreds of Brunelle’s project, “I’m Not a Look!”.
You may have already seen it on social media, where you also came across one of the hundreds of articles on the internet with pictures of non-famous people who look like public figures or celebrities who are very similar to each other.
In fact, one such comparison that has become popular in recent years is the comparison between the founder of the Italian team Ferrari Enzo Ferrari and the German football player of Turkish origin, Mesut Ozil.
What Brunel could not have imagined when she started her project was that it would become the basis for pioneering scientific research.
He was contacted by a group of experts from the Josep Carreras Leukemia Research Institute in Barcelona, Spain, who are trying to understand the physical similarities between individuals without family ties.
The study was led by Manel Esteler, director of the institute and professor of genetics at the University of Barcelona Medical School, and he told BBC News Mundo about the impressive results.
In August, the results of the research, which began in 2016, were published in the scientific journal Cell Reports.
At the molecular level, the authors explained, the study aims to “distinguish random humans who objectively share facial features.”
These are individuals who, because of their “great similarity”, are colloquially called marital.
The researchers contacted Brunel and 32 volunteer pairs who participated in their project.
Images of their faces were analyzed using three facial recognition programs, such as those used, for example, at airports, in the police or to unlock cell phones.
“These are programs that tell you how similar one face is to another,” Esteller explained.
In twins, for example, the similarity detected by these programs reaches 90%-100%.
In the study, it was used to determine the degree of “similarity” of faces and a “high” percentage was found.
“The number of couples associated with at least two programs was very high (75% similarity out of 25 out of 32),” the institute said in a statement.
According to Esteller, this is “very close to a human’s ability to identify identical twins.”
In half of the pairs, all three programs found associations, that is, 16 very similar pairs.
Results
The doctor said the researchers analyzed the participants’ “biological materials”, something that was a bit “complicated” to obtain because they were “in different countries”.
Thus, DNA samples from saliva were collected and analyzed.
“We study this biological material, the genome and two other components: the epigenome, which is similar to the chemical markers that control DNA, and also the microbiome, the kind of viruses and bacteria we have.”
Genomics, genetics, is what united the “couples,” while epigenetics and the microbiome – aspects related to the environment – kept them apart.
“What the study shows is that the most important thing in these cases is that[couples]have similar genes, similar DNA sequences, and[the similarity]is not because they have families in common, and there is no relationship between them.”
“That’s because chance, of course, ended up creating identical sequences or regions of these people’s DNA.”
In fact, the researchers went back “centuries and centuries” in the volunteers’ family history and “didn’t find any common relatives.”
between sequences
The sequences mentioned by the specialist are crucial to the formation of the distinctive features of our face.
The fact that two people are very similar is “like playing the lottery”: it is very difficult to win a prize, but you can be lucky.
“These two people, although not related to each other, end up having genetic variants that give them the same look.” That is, some characteristics of their DNA are similar.
Imagine that both people share a variable that makes their eyebrows thicker, another that makes their lips thicker, another that makes them have a certain type of chin, and so on.
“Together, all of these variables make their faces look alike. Similarity can be expressed as a percentage and has to relate exactly to the different degrees to which genetic variants are involved.”
beyond the physical
This study is groundbreaking in the field of genetics because, as Sarah Kota noted in Smithsonian Magazine, “It may seem obvious that people with similar facial traits will also have some of the same DNA. No one has scientifically proven this yet.”
But there is also something beyond the physical. Volunteers were asked to fill out a questionnaire with more than 60 questions about their lifestyle habits “to see if they were similar in that too, and in some cases there were similarities,” the professor said.
Other physical aspects such as weight, age and height were also analyzed. The study found that of the 16 highly similar couples, “many were of the same weight, and analysis of biometrics and lifestyle factors showed similarities.”
“Behavioral traits such as smoking and educational attainment were correlated in similar pairs, suggesting that shared genetic variation is not only associated with physical appearance, but may also influence common habits and behaviours,” the statement said.
One aspect that Esteller would like to deepen with this research is its potential application in biomedicine.
“We have identified genes and their variants important in determining the shape of the face, and thus the nose, mouth, forehead, and ears, which may also be implicated in diseases. From the face, we can partially deduce what this person’s genome looks like. This may be useful in preliminary screening for genetic diseases.” “
The goal will be to look for any mutation that makes a person susceptible to a particular disease to help prevent it.
The question of numbers
The researchers admit that the study is small, but they believe it is “working properly,” so they are confident that their results would not change if it were done in a larger group.
“Since the human population now stands at 7.9 billion, it is increasingly likely that these similar occurrences will occur,” Esteller said in the statement.
“A larger set analysis will provide more genetic variants shared between these particular haplo pairs and could also be useful in clarifying the contribution of other layers of biological data to define our faces.”
So is it very likely that we have a doppelganger?
The doctor replied, “Having one of us 100% is hard, but it’s possible that someone who matches us 75% or 80% is already there, because there are so many people in the world.”
After years of photographing very similar strangers, Brunel was intrigued.
“I think people are the same everywhere once you dig a little deeper. We’re kind, whatever we look like!”
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