Dating australai - prince andrew dating angie everhart
In the United States, it is estimated that 2–6% of the population has red hair. In Asia, red hair has been found among the ancient Tocharians, who occupied the Tarim Basin in what is now the northwesternmost province of China.
Red hair can originate from several changes on the MC1R-gene.
It is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin.
It is associated with fair skin color, lighter eye colors (gray, blue, green, and hazel), freckles, and sensitivity to ultraviolet light.
Even if both parents do not have red hair themselves, both can be carriers for the gene and have a redheaded child.
Genetic studies of dizygotic (fraternal) twins indicate that the MC1R gene is not solely responsible for the red hair phenotype; unidentified modifier genes exist, making variance in the MC1R gene necessary, but not always sufficient, for red hair production.
The non-tanning skin associated with red hair may have been advantageous in far-northern climates where sunlight is scarce.
Studies by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation prevents rickets in colder climates by encouraging higher levels of vitamin D production and also allows the individual to retain heat better than someone with darker skin. concluded that red hair is not the result of positive selection but of a lack of negative selection.When henna is used on hair it dyes the hair to different shades of red.Emigration from Europe has multiplied the population of red haired humans in the Americas, Australia, New Zealand and South Africa. the largest population of redheads in the world, at 6 to 18 million, compared to approximately 420,000 in Ireland and 300,000 in Scotland.Red hair (or ginger hair) occurs naturally in 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.The pigment pheomelanin gives red hair its distinctive color.