Compared to blondes or brunettes, redheads are more than twice as likely to avoid going to the dentist—and they may have good reason. The same genetic variant that explains their fiery locks also makes redheads resistant to local anesthesia, such as Novocaine, explaining their dread of dental procedures, University of Louisville researchers reported in Journal of the American Dental Association.
In fact, redheads may need 20 percent more anesthesia, researchers from the same center reported in an earlier study, in which women with bright red hair were compared to those with...
Not long ago, newspapers and magazines reported that, by the end of the century, redheads, of whom I am one, will be extinct. Gone. Kaput. Since then, other scientists have raised doubts about the great redhead extinction theory, especially since the research was conducted by the Oxford Hair Foundation—which is funded by Procter & Gamble, which manufactures hair dye. Still, who can say for sure who is right? I'm sure that, back in their day, the dinosaurs were pretty smug too.
Red hair occurs naturally on approximately 1–2% of the human population. It occurs more frequently (2–6%) in people of northern or western European ancestry, and less frequently in other populations. Red hair appears in people with two copies of a recessive gene on chromosome 16 which causes a mutation in the MC1R protein.
Red hair varies from a deep burgundy through burnt orange to bright copper. It is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin. The term redhead (originally redd hede) has been...
Woman with red hair, Papua New Guinea. Melanesians have a significant incidence of fair hair, caused by a genetic mutation different from European blond and red hair
Several accounts by Greek writers mention redheaded people. A fragment by the poet Xenophanes describes the Thracians as blue-eyed and red haired. Herodotus described the Budini people as being predominantly red haired. Dio Cassius described Boudica, Queen of the Iceni, of the ancient Britons, to be "tall and terrifying in appearance... a great mass of red hair... over her shoulders."
A 2007 report in The Courier-Mail, which cited the National Geographic magazine and unnamed "geneticists", said that red hair is likely to die out in the near future. Other blogs and news sources ran similar stories that attributed the research to the magazine or the "Oxford Hair Foundation". However, a HowStuffWorks article says that the foundation was funded by hair-dye maker Procter & Gamble, and that other experts had dismissed the research as either lacking in evidence or simply bogus. The National Geographic article in fact states "while redheads...
The alleles Arg151Cys, Arg160Trp, Asp294His, and Arg142His on MC1R are shown to be recessives for the red hair phenotype. The gene HCL2 (also called RHC or RHA) on chromosome 4 may also be related to red hair.
In species other than primates, red hair has different genetic origins and mechanisms.
Red hair is the rarest natural hair color in humans. The non-tanning skin associated with red hair may have been advantageous in far-northern climates where sunlight is scarce. Studies by...
A close-up view of red hair
The pigment pheomelanin gives red hair its distinctive color. Red hair has far more of the pigment pheomelanin than it has of the dark pigment eumelanin.
The genetics of red hair, discovered in 1997, appear to be associated with the melanocortin-1 receptor (MC1R), which is found on chromosome 16. Red hair is associated with fair skin color because of low concentrations of eumelanin throughout the body of those with red hair. This lower melanin-concentration confers the advantage that a sufficient concentration of important Vitamin D can be...
Today, red hair is most commonly found at the northern and western fringes of Europe; it is associated particularly with the people located in the British Isles (although Victorian era ethnographers claimed that the Udmurt people of the Volga were "the most red-headed men in the world"). Redheads are common among Germanic and Celtic peoples.
Redheads constitute approximately 4% of the European population. Scotland has the highest proportion of redheads; 13% of the population has red hair and approximately 40% carries the recessive redhead gene....