Red hair beautiful girl Lily Cole |
Red hair varies from a full burgundy through burnt tangerine to shiny copper. It is characterized by high levels of the reddish colored pigment pheomelanin and reasonably small concentrations of the darkish pigment eumelanin. It is linked with fair skin color, freckles, lighter eye colors (gray, blue, hazel, green), and sensitivity to ultraviolet mild
Social reactions have diverse from ridicule to affection; many typical stereotypes exist concerning redheads and they are normally portrayed as fiery-tempered.
The word redhead has been in apply since at least 1510
Origins
Red hair is the rarest normal hair color in human beings. The non-tanning skin affiliated with red hair may have been advantageous in far-northern climates where sunlight is hard to find. Research by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation helps prevent rickets in cooler climates by motivating higher levels of Vitamin D production and also enables the person to retain high temperature better than someone with darker skin. In 2000, Harding et al. determined that red hair is not the outcome of positive selection but of a deficiency of bad selection. In Africa, to illustrate, red hair is chosen against because high levels of sun injure untanned skin. However, in Northern Europe this does not arise, so redheads can become more widespread through genetic drift.
Estimations on the original event of the presently active gene for red hair differ from 21,000 to 101,000 years ago.
A DNA review has concluded that some Neanderthals also had red hair, eventhough the mutation trustworthy for this differs from that which causes red hair in modern humans.
Extinction hoax
Thora Birch Red hair celeb |
A 2007 document in The Courier-Mail, which offered the National Geographic mag and unnamed "geneticists", claimed that red hair is likely to die out in the near future. Other personal blogs and media sources ran similar stories that linked the research to the magazine or the "Oxford Hair Foundation". However, a HowStuffWorks document tells that the foundation was funded by hair-dye maker Procter & Gamble, and that other gurus had ignored the research as either inadequate in facts or simply fake. The National Geographic document in fact states "while redheads may decrease, the prospective for red isn't going away".
Red hair is triggered by a fairly exceptional recessive gene, the appearance of which can skip generations. It is not likely to vanish at any time in the not far off future.
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