In the UK red hair is
generally associated with people of Celtic descent, i.e Scotland and Ireland. It
is believed the people of Scotland came from 5 different ethnic groups who
occupied or invaded northern Britain in the dark ages. In all of recorded
history, red-haired people have never been mentioned as a group except by the
The 'Picts' where foes who the Romans fought and were described as having red-hair and 'large limbs' by Roman historian Tacitus. Modern historians with the help of anthropologists have placed red-hair as a unique characteristic belonging to the Picts, who were characteristic to what is now regarded as Scottish.
As far as the world-wide distribution of red-hair is concerned, it would be
fair to say that the majority may well have descended from this North-Western
European region, although as with all variations between people, mutations in
genes can occur and be maintained in any population provided there is no
detrimentus effect to the populations growth.
The melanocortin-1 receptor (MC1R) is a regulator of eu- and phaeomelanin production in the melanocytes and mutations in this gene are known to cause coat colour changes in many mammals. Studies on Irish and Dutch populations have significantly linked variations in the MC1R gene to red-hair.
Also, so called 'loss-of-function' mutations in the human MC1R gene are known
to be common and have recently been shown to be associated with red-hair. One
other interesting point is that recent work has shown that some variants on the
MC1R gene may be preferentially associated with hair colour rather than
Because the primary function of melanins is thought to be for
both 'photoprotection' and 'photosensitising` (eu- and phaeomelanins
respectively), this offers reason to suggest that MC1R variants (most red-heads)
are a risk factor, possibly independant of skin type, for melanoma
Unfortunately this assumes that MC1R mutations occuring in 'hot-climates' would result in high mortality rates occuring before age of parenthood which is probably unlikely. Other than that, I can't think of any other reason to suggest why red-hair originated in north-west Europe other than by random chance.