Have you ever believed that you have an identical twin somewhere that is unrelated to you? Then you might be tied to your “doppelgänger.”
It seems there is a lot more to look alike twins or doppelgängers than meets the eye. A report published in the journal Cell Reports on August 23, 2022, explained that people with similar or identical face features probably share genetic variations.
Human similarity appears to go beyond superficiality
It is difficult to distinguish between the strengths of nature and nurture. While twin studies are a common type of genetic studies, the ‘market’ for doppelgängers is somewhat untapped.
François Brunelle, a Canadian artist, has been tracking and identifying look alikes all around the world since 1999 by exploiting the internet’s broad reach. He worked on the “I’m not a look alike!” photography project, which was after he discovered his own look alike, Rowan Atkinson – an English actor.
Researchers are now using the Brunelle catalog to learn more about what makes us human and what makes us unique.
The study focus
The current research aims to determine whether there is a genetic foundation for the coincidence of similar face traits among unrelated humans. We propose that these same determinants are related to both the physical and behavioral characteristics that make up people.
The current study draws on 64 photographs of look alikes recruited from francoisbrunelle.com to determine their level of similarity. The study participants also filled out extensive questionnaires on their lifestyles and submitted their saliva for DNA testing.
The researchers employed three different facial recognition algorithms to objectively assess the resemblance of the pairs after receiving their headshot photographs. All three algorithms classified 50 percent of the study participants as twins (doppelgängers).
“This special sample collection has encouraged us to assess how epigenomics, genomics, and microbiomics can influence human resemblance,” says senior author and biomedical scientist Manel Esteller from the Josep Carreras Leukaemia Research Institute in Barcelona, Spain, in a press release.
What did the researcher discover?
The study examined the DNA of each pair to determine whether the DNA of these 16 pairings was comparable.
After the genetic examination, the researchers found that 9 of the 16 pairs “clustered together. This is based on 19, 277 common genetic variants in 3,730 genes, many of which are related to body and face features.
When the same software was used to assess 16 lookalike pairs, the results were comparable to those of identical twins.
The results from the DNA analyses also showed that some unrelated people with remarkably identical faces also share some correlated lifestyle features. These include physical traits — for example, height and weight — and behavioral traits, such as education and smoking.
The New York Times reports that experiences can affect DNA and the genes that are “on” and “off,” which is what scientists refer to as epigenomes.
Moreover, the microbiome—a combination of viruses, fungi, and bacteria – that lives in us is influenced by the environment.
Even though the participants’ genomes were comparable, the study discovered variations in their microbiomes and epigenomes.
The researchers emphasized that “Genomics clusters them together, and the rest sets them apart.” Their individual questionnaires indicate that they communicate on a deeper level.
Despite the tiny sample size, the authors claim that the results are “remarkable.”
The authors write, “These findings offer hints about the genetic background underlying our facial features and possibly other physical and psychological characteristics. It also shows how much of who we are and what makes us unique, which is inherited or acquired over the course of our existence.”
Results from genetic analyses
Genetic analyses found look alikes to ultimately share similar genetic profiles, despite that they were unrelated. However, individual participants varied in how their life impacted their genomes.
For instance, environmental factors like diet, exercise, and smoking have a significant impact on each person’s microbiome.
This means that even among people with identical genetic make-ups, the bacterial life in our guts varies greatly from person to person.
The same holds true for each twin’s epigenome. The epigenome explains the chemical alteration made to DNA coiled strands that can turn genes on or off. There was even variation among ultra look alikes in the current study.
How the current study relates to the previous studies
This work adds to earlier research suggesting that specific parts of DNA are responsible for the structure of the human face, especially the nose.
That doesn’t necessarily imply that look alikes or doppelgangers are long-lost twins or soul mates. None of the subject participants in the current study inherited their genes from the same recent relatives. Their genetic resemblances represent a particular subset of human similarities that might be employed to forecast an individual’s growth and aging.
“We provided a special insight into the molecular characteristics that might affect how the human face develops,” said Esteller.
Esteller and his team were motivated to further investigate the phenomena as more individuals reported having a virtual twin without sharing a genetic parent.
Zach Braff and Dax Shepard have consistently been a popular celebrity doppelgänger duo.
Study limitations
The study’s tiny sample size and usage of 2D black-and-white photos are both drawbacks. The study’s subjects were large of European ancestry, which makes it challenging to extrapolate from the results.
Researcher’s conclusion
A press release explained that overall, the evidence “suggests that shared genetic variation not only corresponds to comparable physical appearance but may also impact common habits and behavior.”
Esteller stated in the same press release that “we gave a unique perspective into the molecular traits that may influence the creation of the human face.”
“These findings about look alikes will have long-term forensic medicine consequences. For instance, reconstructing a criminal’s face from DNA — and in genetic diagnosis — the photo of the patient’s face will give clues as to which genome he or she has,” Esteller said.
“We contend that the same variables have an impact on people’s physical characteristics as well as their behaviors. The ultimate challenge would be to forecast the human face structure based on the multiomics landscape of the individual,” Esteller adds.
