Doppelgängers share strikingly similar physical characteristics—they look so alike that, at times, these two unrelated people could easily pass for twins (or, at least, siblings).
People with very similar faces also have many of the same genes and lifestyle habits, according to a new study published Tuesday in the journal Cell Reports.
It may appear to be a given that people with similar facial features would have some of the same DNA, but no one had previously proved this scientifically. Researchers can now find and research doppelgängers thanks to the internet.
Scientists teamed up with Canadian photographer François Brunelle to study what was going on at the genetic level among look-alikes. Since 1999, Brunelle has been traveling across the world for his “I’m not a look-alike!” project, in which he photographs strangers who seem to be virtually identical.
Researchers asked 32 pairs of Brunelle’s models to answer questions about their lifestyles and submit samples of their DNA.
To find out if the similarities went beyond skin deep, the researchers looked at the participants’ DNA. They discovered that nine of the 16 extremely similar-looking pairs had many comparable genetic variations known as single nucleotide polymorphisms in their DNA. These doppelgängers are “virtually identical,” according to Ed Cara of Gizmodo, a geneticist who leads Spain’s Josep Carreras Leukaemia Research Institute.
Doppelgängers, or “human doubles,” not only have physical similarities but also often share lifestyle habits like weight, height, smoking history, and education levels.
But even though they had nearly-identical genes and features, the look-alikes had very dissimilar microbiomes (communities of helpful and harmful microbes that live on/in human bodies) and epigenomes (variations in expressed traits based on experiences from past generations). From a nature vs. nurture perspective, this suggests that its DNA instead of environmental factors or shared life experiences is primarily responsible for how much alike doppelgängers look.
In addition to resolving one of life’s long-standing mysteries, the research could have major medical implications down the road. People with similar DNA may be collectively vulnerable to certain genetic illnesses, so doctors might use facial analysis as a quick and easy pre-screening tool in the future, Sarah Knapton reports for the Telegraph.