contribution: Mike Original: https://www.livescience.com/why-men-red-beards.html
are relatively rare for people with red hair - only 1% to 2% are born. So if you see a man with a reddish or even all red beard you may be able to see the light in both eyes even though he is obviously not a carrot head.
these strange beards especially in men with dark blonde blonde even white hair what is the scientific basis behind these strange beards?
are hair follicles that do not escape the eyes of researchers such as Nina Jablonski a professor of anthropology at Pennsylvania State University. Her research focuses on the biology of hair tone. "I've observed that many people especially young men have red beards red hair some have red beards some have light brown golden or reddish brown hair" she told live science.
according to the telegraph most of the redheads live in Celtic countries such as Scotl Irel Wales followed by Engl Nordic countries. Perhaps predictably the presence of these redheads is due to a genetic mutation. Specifically a gene called "MC1R" is mutated which controls the production of pigment in hair cells. In addition there are also problems such as fair skin poor tanning ability poor pain which may explain why local anesthetics have poor effect on red hair people. The color of
hair is determined by the proportion of two different pigments. Eumelanin will lead to black while panmelanin will lead to red. People with dark or dark brown hair are likely to have only eumelanin or at least it's the main pigment. And blonde people these two kinds of pigment content than black hair red hair friends to be less. People with red hair of course also have melanin. One of the functions of
MC1R gene is to code a protein called melanocortin whose job is to convert red pigment into melanin. But if a person's gene has a double mutation the protein it produces is less efficient leading to a red lock.
what happens when a person has a red beard brown hair? The answer says Jablonski is that there are some strange genes at work.
"this is almost certainly due to the different expression of MC1R in the hair follicles of beard scalp hair which results in different mixing of dark brown melanin yellow red phenanthrene" Jablonski said.
in other words the same gene has different performance in different parts of the body which may be because the MC1R gene is only a single mutation rather than a double mutation - that is this person is actually the carrier of the red hair gene.
also appear in some men as they grow older - usually after their 40th birthday probably because the pigment producing cells in scalp hair beard hair age at different rates Jablonski said.