Ireland is known for its concentration of redheads, but where did this come from?
It comes as Friday marked World Redhead Day, which is used to celebrate everyone who has natural red hair.
Professor Declan McKenna is Associate Head of the School of Biomedical Sciences at Ulster University - and a redhead.
He told Moncrieff redheads have been around for longer than we think.
"A lot of people listening might be thinking, 'I know that redheads come from the Celtic tribes or maybe the Vikings or Germanic tribes.
"Really that's too early in history; you need to almost go back another 10,000 to 50,000 years to the first population migration out of Africa.
"The first people migrating out of Africa across the Arabian peninsula would have settled in and around what [is] now central-south Russia".
Prof McKenna said the movement continued across the continent.
"From there they would have migrated east and west across the world and across the continent," he said.
"Genetic historians have noticed that that's where the first indication of red hair has popped up from a genetic point of view.
"It seems that people who migrated to the West, where we are now, were the ones who carried with them that variant gene that causes red hair.
"Of course, you have the mixing of populations; for example, the Vikings would have taken a lot of Celtic slaves with them.
"That has meant the gene for ginger hair has sort of been kept isolated and preserved in these populations in this part of the world".
Prof McKenna said anyone in Africa with the gene that causes red hair - called MC1R - may not have fared too well.
"In all likelihood anyone born with that in Africa, if indeed that happened 60,000 or 70,000 years ago, probably wouldn't have fared too well under the searing tropical heat.
"At northern latitudes, when they moved up into Europe, that would have been less of an issue.
"We don't get as much sun, we actually may be at an advantage with having fair skin because we can better use the UV light of the sun to make vitamin D.
"That's a working hypothesis - people have argued back and forth about it - but it seems quite plausible".
Prof McKenna said a concentration of redheads in Ireland could also be explained by our isolated geography.
"If you think about Ireland years ago, an island nation with only a few nomadic people living on it, they wouldn't really have come into contact with a lot of people.
"There would have been a lot of intermarrying, a lot of interbreeding and in small populations that means that genes that are recessive - like the red hair gene - would have been preserved in the population," he added.