How DNA can reveal the eye and hair color of the longtime dead
Researchers have used genetic information to determine the appearance of a World War II general
Years of scientific research could finally put to rest an important question: What color was George Washington's hair, really?
Scientists from the Netherlands and Poland have come up with a new system that uses DNA samples to determine the hair and eye color of the deceased. The technique is called HIrisPlex, and it uses 24 different points in the human genome to determine what someone looked like long after their bodies have decomposed. In this case, it was used to accurately figure out the hair and eye color of a long-dead Polish war hero. LiveScience explains:
Researchers analyzed DNA from Gen. Wladyslaw Sikorski, who was born in 1881 and died in 1943. During World War II, Sikorski was commander-in-chief of the Polish Armed Forces and was also prime minister of the Polish government in exile. He died in an airplane crash at Gibraltar. By analyzing genes from one of his teeth, the researchers confirmed he had the blue eyes and blond hair seen in portraits painted many years after his death.
The system isn't perfect. Researchers say it can determine blue or brown eyes with about 94 percent accuracy. Hair color, on the other hand, is trickier territory: The technique can establish blond hair with an accuracy rate of 69.5 percent; brown hair, 78.5 percent; red, 80 percent; and black, 87.5 percent.
The age of the DNA sample matters too. Genetic information unravels as it ages, which is why the further back in time you go, the less accurate a reading you're likely to get.
"This system can be used to solve historical controversies where color photographs or other records are missing," geneticist Wojciech Forensics tells LiveScience. But the technique has perfectly valid modern day applications as well. The system can be used to identify the hair and eye colors in forensics cases, for example, especially when the body is beyond recognition. Let's hope SVU's producers are taking notes.