There is, however, nothing accidental about their tresses according to a new study, which shows blondes can thank a tiny genetic mutation - a single letter change from an A to a G among the 3 billion letters in the book of human DNA. (Agencies)
Therefore, it is now clear that: they do have something special in their genes. The new research reveals how a single genetic tweak is enough to create blond hair in people.
"This particular genetic variation in humans is associated with blond hair, but it isn't associated with eye colour or other pigmentation traits," said study leader David Kingsley, a Howard Hughes Medical Institute investigator at Stanford University.
He said the research shows how a specific gene "switch" might control colour changes in human characteristics.
Kingsley has spent much of his career studying a fish known as the three-spined stickleback in an effort to better understand evolution.
His research uncovered a gene that affects the fishes' pigmentation, and scientists decided to see if it has a similar effect in other species, like humans. Turns out it does.
"The very same gene that we found controlling skin colour in fish showed one of the strongest signatures of [gene] selection in different human populations around the world,"
In the new study, researchers found that a single letter of genetic code separates people with different hair colours.
"The genetic mechanism that controls blond hair doesn't alter the biology of any other part of the body," Kingsley said. "It's a good example of a trait that's skin deep — and only skin deep."
"Despite the challenges, we now clearly have the methods to link traits to particular DNA alterations," Kingsley said.
"I think you will see a lot more of this type of study in the future, leading to a much better understanding of both the molecular basis of human diversity and of the susceptibility or resistance to many common diseases," he added.
There is, however, nothing accidental about their tresses according to a new study, which shows blondes can thank a tiny genetic mutation - a single letter change from an A to a G among the 3 billion letters in the book of human DNA.