To search for an underlying genetic blueprint, Myles and his colleagues collected saliva and hair samples from 1209 Solomon Islanders. Population genetic studies usually compare thousands of individuals, but the researchers predicted they could detect differences in a much smaller sample because of the stark contrast between the islanders' blond and dark locks. 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. Switching one "letter" of genetic code-replacing a "C" with a "T"-meant the difference between dark hair and blond hair. A similar mutation creates blond mice by reducing the melanin content in their fur.
Blond Solomon Islanders carry two copies of this mutant gene, which is present in 26% of the islands' population, the team will report in tomorrow's issue of Science. The gene is recessive, which means that blonds inherit it from both parents. 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.
http://news.sciencemag.org/sciencenow/2012/05/the-origin-of-blond-afros-in-mel.html?ref=hp
Blond Solomon Islanders carry two copies of this mutant gene, which is present in 26% of the islands' population, the team will report in tomorrow's issue of Science. The gene is recessive, which means that blonds inherit it from both parents. 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.
http://news.sciencemag.org/sciencenow/2012/05/the-origin-of-blond-afros-in-mel.html?ref=hp
