The variation of human phenotypes has given rise to a number of anthropological puzzles, including the "European" features of some Mandan native Americans, and the red-haired mummies of China. One such apparent anomaly - blond hair in South Pacific islanders - now appears to have been adequately explained by a single gene mutation rather than by prehistoric cultural diffusion.
Pay a visit to Melanesia's Solomon Islands, 1800 kilometers northeast of Australia, and you'll notice a striking contrast: about 10% of the dark-skinned islanders sport bright blond afros... Human hair color is a trait usually governed by many genes, but study author Sean Myles, a geneticist at Nova Scotia Agricultural College in Truro, Canada, suspected things might be simpler in the Solomon Islands because he saw almost no variation in shades of blond hair. "It looked pretty obvious to me that it was a real binary trait. You either had blond hair or you didn't," says Myles...It's a curious coincidence that this population lives in a geographic area called Melanesia. Related past posts: Caucasian mummy in China - had 28 oz. of marijuana and The mummies of Urumchi.
They compared the entire genetic makeup of 43 blond and 42 dark-haired islanders. The two groups, they found, had different versions of a crucial gene, one that coded for a protein involved in pigmentation... The researchers did not find the mutation in DNA samples of 941 individuals from 52 other populations around the world, including European countries. "It's a great example of convergent evolution, where the same outcome is brought about by completely different means," says Myles...
The results, says Myles, help deconstruct a Eurocentric view of the world in thinking about where blond hair comes from.
Further details at Science. Via Neatorama. Photo credit: Sean Myles