Well, here's something that's a little freaky or potentially cool, depending on your perspective: Scientists report that there's probably someone out there who looks very much like you—or almost exactly like you—and they probably share some of your DNA, even though you're not relatives. Read on to find out how that could be, why it's happening, and why some experts are worried about this scientific discovery.
"I'm Not a Look-Alike!"
It all started with a viral photo project called "I'm not a look-alike!" by Canadian photographer Francois Brunelle. For years, he's been taking pictures of people who are doppelgängers—they look like they could be twins, although they're strangers. Scientists took note of the photos and studied the DNA of 32 sets of look-alikes. Read on to find out what they found.
Facial Recognition Software Found Eerie Matches
According to the study, published this week in the journal Cell Reports, the scientists used facial recognition software to assess the similarities in their faces. "Sixteen of those 32 pairs achieved similar overall scores to identical twins analyzed by the same software," the New York Times reported.
DNA Of Look-Alikes Was Also Similar
Analyzing the DNA of those 16 duos, the researchers discovered they shared significantly more genes than the other 16 pairs that the software determined were less similar.
"These people really look alike because they share important parts of the genome, or the DNA sequence," Dr. Manel Esteller, a researcher at the Josep Carreras Leukaemia Research Institute in Barcelona, Spain, told the Times. "That people who look more alike have more genes in common "would seem like common sense, but never had been shown."
"The System Is Repeating Itself"
The scientists point out that there's more to our makeup than DNA. Environment plays a role, and even though the pairs may look alike and share DNA, parts of their genetic code that's influenced by environment and lifestyle were found to be different.
So what fundamentally explains these identical strangers? There are only so many human faces to go around, and some are being recycled. "Now there are so many people in the world that the system is repeating itself," said Esteller.
Some Experts Concerned By Possible Applications
The researchers' findings could have widespread implications, such as helping doctors predict, diagnose, and treat disease.
"There seems to be something pretty strong in terms of genetics that is making two individuals who look alike also having genome-wide similar profiles," Olivier Elemento, director of the Englander Institute for Precision Medicine at Weill Cornell Medicine in New York, told the Times.
But there are also possibilities that concern experts, such as that DNA could be used to build facial composites of crime suspects. "We've already seen plenty of examples of how existing facial algorithms have been used to reinforce existing racial bias in things like housing and job hiring and criminal profiling," Daphne Martschenko, a postdoctoral researcher at the Stanford Center for Biomedical Ethics, told the Times. The study "raises a lot of important ethical considerations," she said.