The mystery of the black blond Solomon Islands

Previous studies have shown that pigmentation is largely hereditary, but also indicate that evolved to adapt to the sun's ultraviolet rays. Thus, the population near the equator have a darker skin and hair. However, this population of the Solomon Islands, east of Papua New Guinea, differs from this trend.

In the absence of a plausible scientific explanation, the island common sense credits that the color would be a result of excessive sun exposure, or a diet rich in fish. Another explanation is based on the genetic inheritance of distant ancestors, as European merchants who have visited the archipelago in the past.

Now these hypotheses, however, were felled by researchers at Stanford University in the United States, directed by Nic Timpson, the Causal Analysis Center in Translational Epidemiology, University of Bristol, UK. According to a study published in the journal Science, the genetic variant responsible for blond hair of the islanders is different from what cause the same characteristic in Europe.

-. "The natural blonde hair is a surprisingly rare trait in humans, which is associated typically with inhabitants of the Scandinavian countries and northern Europe Our findings not only help explain the fascinating differences in these physical characteristics, but also stress the importance genetic mapping in isolated populations to help shed new light on the epidemiology of diseases, "said Nic Timpson.

In reaching this conclusion, the team collected samples from a group of Melanesians, 43 with blond hair and 42 with dark hair, and performed a genetic analysis to compare their genomes. The results identified a region of the gene responsible for the change in hair color, called TYRP1, which is known to influence pigmentation in humans. Only the variant found in the blond hair of the inhabitants of the Solomon Islands is not found in the genomes of Europeans.

- "This case does away with any simplistic notion we have about race," says geneticist Carlos Bustamante, one of the authors of the study. - "We humans are beautifully different, and this is just the tip of the iceberg."