Naturally blond hair is rare in humans. But dark-skinned blondes are truly unique. They do exist though. When visiting the Solomon Islands, you will be amazed by the striking blond hair of 5 to 10 percent of its inhabitants, especially since these Pacific islands are populated by some of the darkest skinned people in the world.
So where does the blond hair come from? While they themselves attribute their golden locks to a diet rich in fish or the constant exposure to the sun, new research shows that it all comes down to simple genetics.
A team of researchers traveled to the Solomon Islands and analyzed saliva samples from more than 1,000 islanders, looking closely at a subset of the samples — from 43 blond and 42 dark-haired islanders. They were soon able to identify the single gene responsible for the variance in hair color. Called TYRP1, the gene is known to influence pigmentation in humans.
The lab analysis began in September 2010 and “within a week we had our initial result,” said study researcher Eimear Kenny. “It was such a striking signal pointing to a single gene — a result you could hang your hat on. That rarely happens in science.”
Perhaps most interesting is the discovery that the variant of TYRP1 that causes blond hair in Solomon Islanders is entirely absent in the genomes of Europeans. A finding that debunks theories that the islanders got their blond hair from intermarrying with European explorers.
“The human characteristic of blond hair arose independently in equatorial Oceania,” Kenny said. “That’s quite unexpected and fascinating.”
Co-author Carlos Bustamante, professor of genetics at Stanford, said the study gives good cause for more research on the genomes of rarely studied populations.
Photo: © Sean Myles
Kenny, E., Timpson, N., Sikora, M., Yee, M., Moreno-Estrada, A., Eng, C., Huntsman, S., Burchard, E., Stoneking, M., Bustamante, C., & Myles, S. (2012). Melanesian Blond Hair Is Caused by an Amino Acid Change in TYRP1 Science, 336 (6081), 554-554 DOI: 10.1126/science.1217849