Wednesday, May 16, 2012

Fun Fact: Blonde Hair – A Second and Distinct Evolution

Between five to ten percent of Melanesians, people from a small group of islands northwest of Australia, have blonde hair. It has been postulated that the unexpected occurrence of blonde hair in the dark skinned Melanesians was due to the introduction of Europeans who colonized that area.

Photo: Graham Crumb
New research, however, refutes this postulation and locates the origin of the blonde hair to a unique genetic mutation. After comparing the genes of dark-haired and blonde-haired Melanesians, researchers found a specific mutation on the tyrosinase-related protein 1 (TYRP1) gene that is strongly associated with a larger number the blonde inhabitants studied (30%). The TYRP1 gene codes for an enzyme that is known to influence pigmentation in mice and in humans, but it is not found mutated in Europeans who have blonde hair.

Though the researchers are not quite sure why and how the mutation may have reached such a large concentration in the population, they theorize that blondeness may have been an advantage in competition for mates.

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