What is it about blondes?

Researchers at the University of Edinburgh want men and women with blonde hair to take part in their ongoing work to find out more about the genetics of hair colour.

Dermatology professor Jonathan Rees said: "Curiously, for all the jokes about dumb blondes, we can hardly say anything sensible about blonde hair."

He wants to know what advantages there are to having blonde hair, especially when it seems to make people more prone to burning in sunshine and getting skin cancer.

"The strangest aspect of living in northern Europe is that we get used to seeing people with different hair colours," Professor Rees said.

Medical issue

"We forget that for the majority of the world hair is almost uniformly black, whereas in Europe, red hair and blonde hair is quite commonplace."

It seems logical that having very dark skin in northern latitudes would make people prone to rickets - caused by a lack of vitamin D, which is made in the skin.

But Prof Rees said this was "a just so story" - earlier work the team had done on redheads suggested there was no evolutionary selection at work, the red gene was just "genetic drift".

The gene emerged about 50,000 years ago. People who carried it did not necessarily have red hair but were more sensitive to the sun and were at higher risk of developing skin cancers.

And ultra-violet radiation - sunshine - was used in medical treatments.

"So understanding why people with different hair colours react differently is quite important to us."

So far nothing was known about the way blondness was inherited, Professor Rees said.

So he is looking for people of all ages to help with the two-year project, ideally who live in or near Edinburgh and can travel to Edinburgh Royal Infirmary or the University of Edinburgh to be studied.