One of the most visible features of our personality is our face. Interestingly, identical twins have identical facial features and DNA sequences, but may differ in other biometric parameters. With the rise of the internet, the abiltiy to exchange pictures of people all over the world has made it possible to identify ourselves as virtual twins with people to whom we are not related.
But the lookalikes not only look the same, they also share behavioural characteristics. This can be understood to mean that, in a high percentage of cases, they may share common habits such as smoking, and also traits such as how they respond to education, for example.
However, scientist were also interested in whether there was a scientific basis for the doppleganger phenomenom. So the team, recruited from the work of a Canadian photographer, François Brunelle, who documenting the doppelgangers since 1999. These 32 candidates pairs completed biometric tests, lifestyle questionnaires and had their saliva DNA subjected to genomic analysis. It was shown that 16 of the pairs were found in all three facial recognition program used, and genetic analysis also showed that 9 of the 16 pairs shared genetic differences. The study also highlighted that the similarity did not extend to facial features, but also to other characteristics such as height and weight.
So, the summarize so far, the results overall suggest that shared genetic variation is not only related to similar physical appearance, but also extends to shared habits and behaviors.
The results could supply a molecular basis for future applications such as biomedicine, evolution, and medicine. And in forensic science it could be useful because it could be used to create bioinformatics strategies to find a face from DNA using the genomes of unknown people. In medicine, it could be of great help in inferring a person’s genome from facial analysis and could thus be used as a preliminary screening tool to detect the presence of genetic mutations associated with diseases and to apply early prevention strategies.
The study reveals genetic markers that are critical for the development of the nose, lips and mouth, and completely new determinants of bone and skin structure that give the face its distinctive features. However, environmental markers such as the epigenome or the microbiome are more distinct between look-alikes, so differences between look-alikes may be due to the composition of the microbiome and chemicals that regulate the same DNA sequence. This means that because today’s population is 7.9 billion people, similar repeats are more likely occur. In other words, analyzing larger populations will supply more genetic variants that these pairs share, meaning that it could be useful in clarifying the contribution of other layers of biological data defining our face.
Facts collected by Dezső Sándor