Ana Maria Sanchez and Catherine Romero look like identical twins, but they aren’t. A new study published in the journal shows that people who are alike often share parts of their DNA cell reports.
Canadian photographer François Brunel has traveled the world for years to get lookalike photos of Sanchez and Romero in front of his lens for his project ‘I’m Not A Look! ”, inspired by his resemblance to British actor Rowan Atkinson. The Spanish scientists selected 32 similar ones from Brunel’s work, asked them to fill out questionnaires about their lifestyle and map their DNA.
In the first phase of the research, the scientists applied facial recognition software to images to objectively identify similarities. The researchers continued working with sixteen pairs and found three different algorithms that are very similar, as powerful as identical twins. A comparison of the genomes of those polymorphs showed that nine pairs were similar at more than 19,000 locations in the DNA or in more than 3,700 genes.
first guide
If information about how we are grouped together is stored in our DNA, is it any wonder that phenotypically very similar people also do so at the genetic level? “It’s what you’d expect, but it’s the first time it’s been shown to be effective as well,” says Peter Claes, who researches the genes behind the physical properties at KU Leuven. “The fact that the scientists apparently found fewer genetic similarities in seven of the 16 pairs is actually at least remarkable, but unfortunately they haven’t gone into that in more detail.”
According to Claes, this may also relate to study design. “The researchers used Brunel’s images, where extra effort was made to make people the same,” he says. “Maybe the algorithms that were supposed to assess the physical similarity were a bit misleading because of that.”
The scientists also compared the so-called epigenomes of test subjects. Our genes contain our genetics, but interaction with our environment affects which genes are turned on or off or how active they are. This happens because certain molecules bind to the DNA like some kind of dimer. An environment with too much or too little pollution, too much or too little stress: they can all affect how our genetic code looks. However, in that epigenome, scientists have not found any similarities in the zygote. “We know that epigenetics plays an important role in certain diseases,” says geneticist Paul Cook (UGent). “On our looks, that doesn’t seem like much.”
anticipate faces
Relatively little is known about how we look. To find out how genes and environment define who we are, scientists often conduct research on identical twins. “However, you can’t conclude from this that exactly genes play a role in our appearance,” says Coucke. “Because these twins are completely genetically identical. So looking at unrelated doppelgängers is a smart move.”
About 500 genes have been identified so far that are known to play a role in our appearance. “That doesn’t mean we know exactly what they’re doing,” Claes says. Several years ago, he and his colleagues were able to identify 15 regions of DNA associated with specific parts of the face, such as the forehead and chin. Seven of these genes play a role in nose formation. “But given the complexity of our appearance, it’s possible that thousands of genes are involved,” Claes said.
Have the scientists here identified more than 3,700 genes involved in one hit? That remained to be a sight. “The homologous pairs may not be related to each other, but it cannot be excluded that this part of the overlap is due to the fact that people come from the same geographical area,” Claes says. “For example, the Belgians and the Dutch also show genetic similarities. This study provides an interesting set of genes for further research.”
More insight into the relationship between genes and faces could help scientists predict a person’s appearance based on DNA. This can help determine the shape of the desired offender based on the DNA tracing. It’s far from that yet. “We shouldn’t expect much from this either,” Claes says. “We may never be able to produce any kind of image based on your DNA, just a rough estimate.”
It seems a miracle that somewhere in the world there may be someone who looks like you, but it is not. “Although there are many possibilities for face painting, the variation is also limited,” Claes says. “A nose like Pinocchio and a face like Picasso’s paintings is not possible. Given that we are over 6 billion, it is not surprising that you sometimes come across the same design.”
