A new study by Spanish researchers found that human ‘look-alikes’ with similar facial features also tend to share many genetic similarities, as well as certain lifestyle attributes. It shows that
Research published in journals cell report, provides insight into the molecular genetic mechanisms that contribute to facial construction. By being able to predict facial structure from DNA, the authors say these findings may ultimately have applications in forensics.
Ricky Joshi of the Josep Carreras Leukemia Institute in Barcelona and his colleagues identified 32 unrelated pairs from photographs by Canadian artist François Brunel, who has been collecting photographs of look-alikes since 1999. I collected a photo of the look-alike.
Joshi and his colleagues analyzed the photos using three different facial recognition algorithms to determine the similarity of each pair. Of those, 25 of his pairs were at least classified as “very similar” by two algorithms, half of which he matched on all three, with scores equivalent to identical twins. We then contacted everyone in the selected photos and asked them to complete a lifestyle questionnaire and submit a saliva sample.
Researchers extracted DNA from saliva samples and analyzed it in three different ways. (1) We compared the genomes of each participant by mapping over 4.3 million genetic variants called single nucleotide polymorphisms (SNPs). (2) examined the participants’ “epigenome” by comparing over 850,000 DNA modification sites; (3) RNA-sequencing was used to compare the microbiomes of the participants;
Analysis revealed that 9 of 16 highly similar pairs shared more than 19,200 SNPs in more than 3,700 genes, and these similarities were not due to shared ancestry. In contrast, the epigenome and microbiome had little similarity. Furthermore, these ‘super-look-alikes’ also share physical characteristics such as weight and height, as well as habits and behaviors such as smoking and level of education, suggesting that the shared genetic mutations affect not only their physical appearance but also their lifestyle. It was suggested that the
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This study is limited by the size of the sample, which is not representative of the world population. Thirteen of his lookalike pairs were of European descent, and the remaining three of his were East Asian, South Asian, and Hispanic. Still, we get evidence that people who look alike also behave alike.