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  • You know, redheads take a lot of crap, not only do they fall prey to nicknames like

  • Big Red, Rusty and Daywalker,

  • they also carry a rich history of misunderstanding on their frequently freckled shoulders.

  • In Greek mythology, it was said that redheads turn into vampires when they die.

  • Egyptians particularly enjoyed burning ginger virgins.

  • And a number of alchemist spells called for the fat of a flame-haired man.

  • If that weren't enough, in recent years there have been headlines suggesting that redheads will actually go extinct within this century

  • A lot of the ignorance surrounding red-headedness

  • probably has to do with the fact that although they aren't very rare,

  • redheads aren't very common either.

  • Though certain countries like Ireland and Scotland seem to be hosting

  • perpetual Weasley family reunions,

  • gingers only make up about 1 to 2 percent of the world population

  • and they don't have red hair because they stole hell fire or were conceived during menstruation

  • or bitten by a werewolf as a baby.

  • They get their coppery hue the same way we all get our coloration: from melanin.

  • Hair color is a genetic trait associated with the melanocortin one receptor, or MC1R gene.

  • We all have it nestled on our chromosome 16,

  • but your red-headed friends possess a mutated version of it.

  • This gene gives instructions for making protein receptors

  • located on our melanocytes, the special cells that produce melanin.

  • Melanin is what gives our eyes, hair, and skin their distinct hue and it comes in two varieties:

  • eumelanin and pheomelanin.

  • A person producing mostly eumelanin will have darker hair and skin that tans easily

  • and is better protected from the sun's UV radiation

  • but if you're brewin' mostly pheomalinin, you're gonna have reddish or blonde hair,

  • fair skin that burns easily because it's not naturally protected from the sun.

  • That's why fair folk have an increased risk of skin cancer.

  • It's that MC1R gene that dictates what kind of melanin you get.

  • If the gene is activated,

  • you'll end up with more eumelanin and will be darker complected.

  • If those receptors don't trigger,

  • your cells pump out the fair pheomelanin.

  • We're not exactly sure just how far back the trait goes,

  • but scientists recently extracted a version of the ginger gene

  • from the remains of two Neanderthals indicating that at least some of them were redheads.

  • However, the gene was a variant. Not the one present in modern humans

  • indicating the mutation evolved independently from human red-headedness

  • in an example of convergent evolution. Now you may be wondering why

  • both humans and Neanderthal genes would perpetuate a skin type so prone to sunburns.

  • Well, it has to do in part with geography.

  • People from equatorial regions usually have darker hair and skin to better protect them from the sun's radiation.

  • Whereas fair skin and hair

  • is more prevalent in northern areas with lower levels of sunlight.

  • The farther you move from the equator, the more that selective pressure for darker pigmentation lessens

  • and the mutant MC1R genes are not selected against

  • so they can spread throughout a population.

  • And then, hello Scotland.

  • The successful spread of this mutation may be because fair skin is better at generating vitamin D

  • which could have actually given flame hairs an evolutionary advantage in the perpetually cloudy North.

  • But you may have also heard that gingers are kinda babies

  • when it comes to pain

  • and I hate to say it but there's some truth to that.

  • A couple of studies funded by the National Institutes of Health

  • found that redheads are actually more sensitive to thermal pain, or excessive heat and cold,

  • and that they actually required, on average, nearly 20 percent higher doses of anesthetic than their dark-haired counterparts.

  • And researchers aren't entirely sure what's going on here

  • but one hypothesis connects pain tolerance to that tricksy MC1R gene.

  • Since the gene is responsible for the receptors of pigment-producing hormones,

  • they may also interact with similar molecules like endorphins,

  • our body's natural painkillers.

  • And finally, what about that great imminent ginger extinction?

  • That, I can tell you, is bogus.

  • Yes, the mutation is a recessive trait meaning that both parents have to carry

  • the allele or gene variant for it to produce a red-haired offspring.

  • But that still means that even if say,

  • four percent of the population actually has red hair, perhaps thirty percent still carry that gene

  • keeping the potential for ginger generations alive and not just in the UK.

  • So rest assured gingers are gonna be passing along their genes and supporting the sunscreen industry for a very long time.

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You know, redheads take a lot of crap, not only do they fall prey to nicknames like

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The Truth About Gingers

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    羅紹桀 posted on 2016/04/24
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