The largest study of the genetics of hair colour has identified eight genes linked to redheadedness.
Previous research had suggested that just one gene was responsible for red hair. It was thought that if a child inherited a copy of the MC1R genetic variant from both parents, they would have ginger hair. However, genomic data from 350,000 people who took part in a UK Biobank study found that eight previously unknown genes were linked to red hair.
Professor Albert Tenesa, of the University of Edinburgh's Roslin Institute, said: 'We are very pleased that this work has unravelled most of the genetic variation contributing to differences in hair colour among people.'
The research found that the majority of people with two MC1R copies in fact had blonde or light brown hair. The eight newly identified genes contributed around 90 percent of the heritability of red hair.
In addition, the research revealed that there were nearly 200 genes related to blonde and brown hair.
The research focused on people of white British ancestry because of their greater variation in hair colour, the researchers said.
'Once again, collaborative research is helping to provide answers to some of life's important questions,' said Melanie Welham, executive chair of the Biotechnology and Biological Sciences Research Council, which funded the research.
'[The study] has provided some fascinating insights into what makes us such distinct individuals.'
The research was published in Nature Communications.