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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.

    可以製造大量真黑素的人會有比較黑的頭髮和皮膚,容易曬黑且較能防止太陽的 UV 輻射。

  • 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.

    MC1R 基因決定你能得到什麼樣的黑色素。

  • If the gene is activated, you'll end up with more eumelanin and will be darker complected.

    如果這個基因比較活躍,你會有較多真黑素和較黑的膚色 。

  • 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.

    你離赤道越遠對於需要黑色素沉澱的壓力就越少,突變的 MC1R 細胞就不會作用,所以這個特徵就會在人口中散播。

  • And then, hello Scotland.


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

    這種基因變化的成功地傳播或許是因為白皮膚比較善於製造維他命 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.

    但你可能會聽說過紅髮人非常怕痛簡直像個嬰兒一樣 我很不想承認,但這是有事實根據的。

  • 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.

    學者並不完全確定這之間的關聯但一項假設認為對於痛的忍受度和刁鑽的 MC1R 基因有關。

  • 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.


  • Thank you for watching this SciShow dose and a big thanks to our subscribers on Subbable without whom you would not be watching this.

    感謝收看 SciShow 且大力感謝我們在 Snubbable 上的訂閱者,沒有你們就沒有這支影片!

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    不知道你們會不會希望我們推特美麗的工作室的圖片?或是將你們的訊息放到我們的 doobliedoo?

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  • And if you have an idea you'd like us to cover or a question or comment, leave it for us in the comments below and don't forget to follow us on Facebook and Twitter.


  • And go to and subscribe.

    並前往 訂閱!

You know, redheads take a lot of crap, not only do they fall prey to nicknames like Big Red, Rusty and Daywalker,


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B2 中高級 中文 美國腔 紅髮 基因 黑色素 皮膚 髮色 頭髮

紅髮人即將絕種?不為人知的紅頭髮秘辛 (The Truth About Gingers)

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    羅紹桀 發佈於 2021 年 08 月 12 日