Blond hair was attributed to Caucasians for long, but the Melanesians of Solomon Islands are one among the few groups with blonde hair outside Europe.
These black island people in the South Pacific migrated over a few thousands of years ago.
Melanesia is a subregion of Oceania, extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji.The region consists of most of the islands immediately north, and northeast of Australia and includes the countries of Fiji, Vanuatu, Solomon Islands, New Caledonia, and Papua New Guinea.
The name Melanesia was first used by Jules Dumont d’Urville back in 1832 to denote an ethnic and geographical island group distinct from Polynesia and Micronesia.
Over 90% of the indigenous Melanesian people lead rural lives, and until recently, they practiced cannibalism, head-hunting, kidnapping, and slavery. Yet, under European influence, the population is now predominantly Christian.
Melanesians presently speak over 1,000 languages, which include pidgins and creole languages adapted from trade and socializing even long before the European occupation.
The Solomon Islands are situated in the South Pacific, just Northeast of Australia, between Papua and Vanuatu. It is an independent state within the British Commonwealth.
The popularity of the Melanesian people of the Solomon Islands is due to their dark skin and blond hair. Even though they possess the darkest skin outside of Africa, between 5 and 10 percent have bright blond hair.
Scientists have come up with various theories on the way they got the blond hair, like high fish intake, sun, and salt whitening, and many assumed that it was the result of gene flow — a trait passed on by European explorers, traders and others who visited in the preceding centuries.
According to a study from the Stanford University School of Medicine, the blond hair among the dark-skinned indigenous people of these islands is due to a homegrown genetic variant distinct from the gene that leads to blond hair in Europeans.
Co-senior study author Carlos Bustamante, a professor of genetics at Stanford said:
“Since most studies in human genetics only include participants of European descent, we may be getting a very biased view of which genes and mutations influence the traits we investigate. Here, we sought to test whether one of the most striking human traits, blond hair, had the same — or different — genetic underpinning in different human populations.”
Myles, a former Stanford postdoctoral scholar who is now an assistant professor at the Nova Scotia Agricultural College, had been there in 2004 as a graduate student with Max Planck Institute molecular anthropologist Mark Stoneking, Ph.D., also a co-author of the study, to investigate whether the language variations correlated with genetic variations.
Myles was then fascinated by the ubiquity of blond hair, which was especially common among children:
“They have these very dark skin and bright blond hair. It was mind-blowing. As a geneticist on the beach watching the kids playing, you count up the frequency of kids with blond hair, and say, ‘Wow, it’s 5 to 10 percent.’ That’s not very far off from the proportion of blond-haired people in Europe.”
Myles and Nicholas Timpson, Ph.D., traveled to the remote Solomon islands to collect data.
When the local chief approved their research, they recruited participants and assessed hair and skin color using a light reflectance meter, took blood pressure readings and measured heights and weights. They asked the villagers to spit into small tubes to provide saliva to be used for DNA extraction. In the span of a month, they collected more than 1,000 samples.
They conducted a genetic analysis on saliva and hair samples from 1209 Melanesian Solomon Island residents.
Eimear Kenny, a postdoctoral scholar in Bustamante’s lab, began the analysis in September 2010.
“Within a week we had our initial result. It was such a striking signal pointing to a single gene — a result you could hang your hat on. That rarely happens in science. It was one of the best experiences of my career.”
For the analysis, they selected 43 blond- and 42 dark-haired Solomon Islanders from the opposite 10 percent extremes of the hair pigmentation range.
They found that the Melanesian people have a native TYRP1 gene that is partly the reason for their blond hair and melanin and is distinct from that of Caucasians since it does not exist in their genes.
It’s a recessive gene, more common in children, with hair tending to darken as the individual matures.
After another analysis of genomes from 52 humans from around the world, it was discovered that this mutation doesn’t appear in European genomes. It has developed independently and remained in the Melanesian population.
“So, the human characteristic of blond hair arose independently in equatorial Oceania. That’s quite unexpected and fascinating.”
This makes the gene different from the one responsible for blue eyes, which arose from a single common ancestor between 6,000 and 10,000 years ago. They stated that before then, there were no blue eyes.
Bustamante claims that this discovery solves a nifty genetic mystery, but it also points put the dangers of assuming that genome findings from one population will translate to another. He added:
“If we’re going to be designing the next generation of medical treatments using genetic information and we don’t have a really broad spectrum of populations included, you could disproportionately benefit some populations and harm others.”
Bustamante is seeking funding to analyze the rest of the data gathered.
“For instance, the genetics of skin pigmentation might be different there too — not the same as in Europe or Africa or India. We just don’t know.”
The beauty of the discovery, according to Myles, is that “it’s a great example of convergent evolution, where the same outcome is brought about by completely different means.”
And the beauty of the Melanesians cannot be described with words!