About blond hair in non-‘white’ people

Most people equate light hair with light skin but for Melanesians in the Pacific Islands, a.k.a. Oceania, this  isn’t the case at all as Melanesians typically have skin as dark as many Africans. I’ve known about the existence of ‘black’ people with naturally blond hair for quite a while. I also knew it was an indigenous trait not caused by early European explorers, as was previously assumed.

However, I had no idea about the genetics behind it. According to research by S. Myles, N.J. Timpson and others (geneticists) the blond hair trait has a different genetic origin in Melanesians than in North Europeans. In North Europeans it’s mainly caused by variants in a gene called melanocortin 1 receptor (MC1R), while for the Melanesians it’s predominantly produced by variation of a gene called tyrosinase related protein 1 (TYRP1). There were other genetic variants as well but this TYRP1 was the most prevalent among blond Melanesians, accounting for about 26% of hair colour variation*. In genetics it’s unusual for a single gene to account for such a high frequency of an observable trait. Just like in people of North European descent this gene variant is recessive so a person has to inherit it from both parents to have blond hair.

* With age and sex accounted for (as women and young children possess blond hair more frequently).

Some samples of blond-haired ‘black’ Oceanian children 

This variant of TYRP1 seems to occur only in Melanesians. This completely debunks an old hypothesis that Europeans brought the blond genes to that region when they first ‘discovered’ it in the late 16th century (when Spaniards were searching for the Ophir of biblical King Solomon, hence how the Solomon Islands were named). In the light of current scientific understanding, this hypothesis was flawed from the start since Spaniards never were well-known for having blond hair. After Melanesians NORTH Europeans (which doesn’t include Spaniards or Mediterraneans as they’re from South Europe) are known to have the highest frequency of blond hair on Earth.

This research was published in the journal Science, 4th May 2012. Here’s the link: http://www.sciencemag.org/content/336/6081/554.abstract

S. Myles, one of the researchers, made a telling comment about the current state of genetics and the implications of this research on it. He explained how in medical genomics research is done almost exclusively on people of European ancestry (i.e. ‘white’ people). This means most of the understanding of genetic disease risk comes from the smallest (and incidentally wealthiest) population on the planet. This inevitably ignores the vast majority of human genetic diversity and thus distracts from knowing of them. The comment can be seen at:

http://www.cultivatingdiversity.org/2012/05/03/melanesian-blond-hair-explained/

All very fascinating…

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