The tale of twin strangers
Deccan Chronicle.| Vikram Sharma
Science explains how how two random individuals may display a close match in their facial features
Experts believe that the doppelgnger study provides a rare insight into human likeness by demonstrating that people with extremely similar looks share common genotypes but differ in their epigenome and microbiome.
When Rishi Sunak walked into 10 Downing Street as the youngest Prime Minister of the United Kingdom, former India cricketer Ashish Nehra, sitting far away in Goa, was making news for no actual reason. Sunak’s uncanny resemblance to Nehra and the close-up pics of the duo were all over social media, with some even suggesting how Nehra could get back the ‘Kohinoor’!
Jokes apart, neither are Sunak-Nehra related to each other nor do they share the same ancestors. They belong to different places.
A twin for every one
There are approximately 50 genetic mutations which are responsible for our facial features. The mutations at these positions and their combinations decide the facial feature of a person. They say each and every one of us has a doppelgänger somewhere in the world. Scientists have long wondered how a doppelgänger or look-alike is created.
According to the most recent issue of the journal Cell Reports, doppelgängers share more than meets the eye. People with strikingly similar faces have many of the same genes and lifestyle habits. There are many people across the world with similar DNA sequences. "Mutation and recombination are two basic processes in evolution which bring population variation. However, due to excessive human expansion, it is equally possible to hit a bunch of mutations in two random individuals. This is nature’s beauty," smiles renowned scientist Gyaneshwar Chaubey, known internationally for his extraordinary work in the fields of Biological Anthropology, Medical Genetics and Forensics.
More than skin deep
Although it may appear obvious that people with similar facial features would share some DNA, this had never been scientifically proven. Because of the Internet, researchers can now find and study doppelgängers more easily than before. François Brunelle, a Canadian artist, has been using the Internet’s vast reach to identify and track look-alikes all over the world since 1999. Explaining what goes on at the genetic level among look-alikes, Chaubey, professor in the department of Zoology at Banaras Hindu University (BHU) says there are two kinds of similarities. First, identity by descent (IBD) and second, identity by state (IBS). "In the first case, we inherit these identical mutations from our ancestors, whereas in the second case, though these mutations are similar, we don’t inherit them from our ancestors. They happen independently, but by chance — and all show the same state. This is how two random individuals may display a close match in their facial features," says Chaubey.
Renowned scientist Gyaneshwar Chaubey
Assume that out of 50 mutations, a combination of the first 25 ancestral (non-mutated) and the remaining 25 derived (i.e. mutated) mutations jointly construct face type ‘A’. The person of different ancestry but with the same mutational pattern would exhibit similar facial features regardless of ancestry. "Genetically related people share a large number of DNA segments. This is the foundation of forensics and individual genetics," adds Chaubey.
Rishi Sunak-Ashish Nehra are not the only famous look-alikes. Think of Natalie Portman-Keira Knightly, Katy Pery-Zoeey Deschanel, Penelope Cruz-Salma Hayek and right here in India, Jacqueline Fernandes-Amanda Cerny and Anushka Sharma-Julia Miachels — the list of people and their doppelgängers is really long.
Julia Miachels- Anushka Sharma
Natalie Portman-Keira Knightly
Jacqueline Fernandes-Amanda Cerny
When you see these celebrity ‘twins’ side-by-side, you won’t believe they’re not related.
Similar genomes and characteristics
Doppelgängers not only look identical, they may also exhibit similar behaviours. "In most cases, it is not just the similarities in hair colour, beards, structure of their nose, cheekbones or the shape of their lips — similar-looking people may also have similar behavioural traits. People with genetic similarities have similar weight as well. All of us share 99.9 percent of our DNA but when we share much more, it is likely that we have a lot of facial and also possibly behavioural commonalities," says Anuradha Acahrya, CEO of Mapmygenome.
Anuradha Acahrya, CEO of Mapmygenome
She says our genomes come coded with instructions that regulate how we look and behave and adds that many people who look similar have very similar genomes and also share characteristics.
Experts believe that the doppelgänger study provides a rare insight into human likeness by demonstrating that people with extremely similar looks share common genotypes but differ in their epigenome and microbiome.
Genomics clusters them together, and the rest set them apart, says the study in Cell Reports. "These findings not only provide clues about the genetic setting associated with our facial aspects, and probably other traits of our body and personality, but also highlight how much of what we are, and what defines us, is really inherited or instead is acquired during our lifetime."
Highlights of the study:
• Facial recognition algorithms identify ‘look-alike’ humans for multiomics studies
• Intrapair look-alikes share common genetic sequences such as face trait variants
• DNA methylation and microbiome profiles only contribute modestly to human likeness