地球上为什么有不同颜色的人种（双语阅读地球上真的有蓝色人种吗）

双语阅读

The Fugate and Combs families of Kentucky had blue-looking skin thanks to a rare genetic trait.

肯塔基州的富盖特和库姆斯家族拥有蓝色的皮肤，这要归功于一种罕见的遗传特征。

In the isolated hollows of rural eastern Kentucky, they were known as the blue Fugates and the blue Combses. Collectively they were called the blue people of Kentucky. For more than a century, these Appalachian families passed along an exceedingly rare genetic blood condition that turned their skin a disarming shade of blue.

在肯塔基州东部偏远的乡村地区，他们被称为蓝色的富盖特和蓝色的库姆斯。他们被统称为肯塔基州的蓝人。一个多世纪以来，这些阿巴拉契亚家族遗传了一种极其罕见的遗传血液疾病，使他们的皮肤变成了令人生畏的蓝色。

Embarrassed by their bluish hue, the families retreated even further from society, which only exacerbated the problem. Cut off from contact with the wider population, they married cousins, aunts and other closely related kin, which greatly increased the odds of inheriting the condition.

这些家庭对自己的蓝色感到尴尬，进一步远离社会，这只会加剧问题。他们与更广泛的人群断绝了联系，与表兄妹、姑姑和其他近亲结婚，这大大增加了遗传这种疾病的几率。

As scientists discovered in the 1960s, the mutation that causes the Smurf-like skin is carried by a recessive gene, and it takes two people with that same gene to produce a blue child.

正如科学家在20世纪60年代发现的那样，导致蓝精灵般的皮肤的突变是由一种隐性基因携带的，只有两个拥有相同基因的人才能生出一个蓝色的孩子。

"If you took any random person in the population, maybe one in 100,000 would carry this gene, if that many," says Ricki Lewis, a science writer and author of the textbook "Human Genetics: Concepts and Applications," now in its 13th edition. "But if you're marrying your cousin, it's one in eight. The risk skyrockets if you're sharing blood."

科学作家、《人类遗传学:概念与应用》(Human Genetics: Concepts and Applications)教材的作者里基·刘易斯(Ricki Lewis)说:“如果你在人群中随机抽取一个人，可能十万分之一的人会携带这种基因，如果有那么多的话。”该书目前已出版第13版。“但如果你和你的堂兄结婚，这是八分之一。如果你与他人血液结合，风险会飙升。”

Contents 目录

1. When Two Strangers Lost the Genetic Lottery 当两个陌生人失去了基因
2. Why Their Blood Turned Blue 为什么他们的血会变蓝
3. Is There a Cure for Blue Skin? 有治疗蓝色皮肤的方法吗?
4. What Happened to the Blue People? 蓝人怎么了?

1.When Two Strangers Lost the Genetic Lottery 当两个陌生人失去了基因

Martin Fugate arrived in the unsettled frontier of Kentucky in 1820. He was a French orphan who knew nothing of his lineage. Legend has it that Martin himself may have had a blue tinge to his skin, but not the dark blue skin color of later Fugates.

马丁·富盖特于1820年到达了肯塔基州不安定的边疆。他是个法国孤儿，对自己的血统一无所知。传说马丁自己的皮肤可能是蓝色的，但不是后来富盖兹的深蓝色皮肤。

Martin married a red-headed American woman named Elizabeth Smith and the two set up a homestead on the banks of Troublesome Creek near Hazard County, Kentucky. Elizabeth had pale white skin, almost translucent. What neither she nor Martin could have known is that they both carried the recessive gene for a rare hereditary blood disorder called methemoglobinemia.

马丁娶了一位名叫伊丽莎白·史密斯的红发美国女人，两人在肯塔基州阿扎尔县附近的麻烦溪岸边建立了一座宅院。伊丽莎白皮肤白皙，几乎是半透明的。她和马丁都不知道的是，他们都携带了一种罕见的遗传性血液病——高铁血红蛋白血症的隐性基因。

"The beginning of this story is so wild because Martin moved to Kentucky from Europe and married a complete stranger, a nonrelative who just happened to have the same mutation," says Lewis. "That's crazy."

刘易斯说:“这个故事的开头很疯狂，因为马丁从欧洲搬到肯塔基州，娶了一个完全陌生的人，一个没有血缘关系的人，只是碰巧有同样的突变。”“这太疯狂了。”

Martin and Elizabeth had seven children, four of whom were "bright blue" according to Fugate family lore.

马丁和伊丽莎白有七个孩子，根据富盖特家族的传说，其中四个是“亮蓝色的”。

Since rail lines and paved roads didn't make it out to Troublesome Creek for nearly a century, the blue recessive gene was passed down to generations of Fugates and neighboring families, all of whom came to be known as "the blue people of Kentucky."

由于近一个世纪以来，铁路和铺装路都没有传到Troublesome Creek，蓝色隐性基因就传给了富盖特和附近的家庭，他们都被称为“肯塔基州的蓝色人”。

2.Why Their Blood Turned Blue 为什么他们的血会变蓝

This 25-year-old woman had symptoms of weakness, fatigue, shortness of breath, and skin discoloration. She was diagnosed with methemoglobinemia.

这名25岁的女性有虚弱、疲劳、呼吸短促和皮肤变色的症状。她被诊断为高铁血红蛋白血症。

Methemoglobinemia is a blood condition, not a skin condition. It has nothing to do with melanin, the amino acid that gives people darker skin tones. In people with methemoglobinemia, the skin appears blue because the veins beneath the skin are coursing with dark blue blood.

高铁血红蛋白血症是一种血液疾病，而不是皮肤疾病。这与黑色素无关，黑色素是一种使人肤色变深的氨基酸。高铁血红蛋白血症患者的皮肤呈蓝色，因为皮肤下的静脉中流淌着深蓝色的血液。

If you stayed awake in high-school biology, you might remember that blood is red because red blood cells are packed with proteins called hemoglobin. Hemoglobin gets its red color from a compound called heme that contains an iron atom. That iron atom binds with oxygen, which is how red blood cells circulate oxygen throughout the body.

如果你在高中生物课上没有睡觉，你可能会记得血液是红色的，因为红细胞中充满了一种叫做血红蛋白的蛋白质。血红蛋白的红色来自一种叫做血红素的化合物，它含有一个铁原子。铁原子与氧结合，这就是红细胞在全身循环氧气的方式。

Oxygen, or a lack of oxygen, is what turns the blood from red to blue in people with methemoglobinemia. A mutated gene causes their bodies to build up a rare form of hemoglobin called methemoglobin that can't bond with oxygen. If enough blood is "infected" with this faulty type of hemoglobin, it changes from red to an almost purple-ish dark blue.

缺氧是高铁血红蛋白血症患者血液由红变蓝的原因。一种突变的基因导致他们的身体产生一种罕见的血红蛋白，称为高铁血红蛋白，这种血红蛋白不能与氧气结合。如果有足够多的血液被这种有缺陷的血红蛋白“感染”，它就会从红色变成几乎是略带紫色的深蓝色。

For the Fugates, family members expressed the gene to varying degrees. If their blood had a lower concentration of methemoglobin, they might only blush blue in cold weather, while people with higher concentrations of methemoglobin were bright blue from head to toe.

对于富盖特夫妇来说，家族成员在不同程度上传递了这种基因。如果他们的血液中高铁血红蛋白浓度较低，他们可能只在寒冷的天气里脸红成蓝色，而高铁血红蛋白浓度较高的人从头到脚都是亮蓝色。

3.Is There a Cure for Blue Skin? 有治疗蓝色皮肤的方法吗?

Methemoglobinemia is one of the rare genetic conditions that's treatable with a simple pill.

高铁血红蛋白血症是一种罕见的遗传性疾病，可以用简单的药物治疗。

The man who discovered the cure for methemoglobinemia was Madison Cawein III, a hematologist (blood doctor) at the University of Kentucky who heard tales of the "blue people" and went looking for specimens in the 1960s.

发现高铁血红蛋白血症治疗方法的人是麦迪逊·卡温三世(Madison Cawein III)，肯塔基大学的血液学家(血液医生)，他听说了“蓝色人”的故事，并在20世纪60年代去寻找样本。

Cawein got lucky when a brother and sister named Patrick and Rachel Ritchie walked into a Hazard County clinic. "They were bluer'n hell," said Cawein in a 1982 interview with Science 82. "I started asking them questions: 'Do you have any relatives who are blue?' then I sat down and we began to chart the family." He remembered that the Ritchie siblings "were really embarrassed about being blue." However, the disorder didn't seem to cause any special health problems.

卡温很幸运，一对名叫帕特里克和瑞秋·里奇的兄妹走进了阿扎尔县的一家诊所。1982年，Cawein在《科学82》杂志的一次采访中说:“它们比地狱还要蓝。”我开始问他们问题:‘你有亲戚是蓝色的吗?’然后我坐下来，开始绘制这个家庭的图表。”他记得里奇兄弟姐妹“对自己的肤色感到非常尴尬”。然而，这种疾病似乎并没有导致任何特殊的健康问题。

The condition was clearly genetic, but the key for Cawein was reading reports of hereditary methemoglobinemia among isolated Inuit populations in Alaska where blood relatives often married. He knew the same thing was happening in this secluded corner of Appalachia.

这种情况显然是遗传性的，但对Cawein来说，关键是在阿拉斯加孤立的因纽特人中阅读遗传性高铁血红蛋白血症的报告，那里的血亲经常结婚。他知道同样的事情也发生在阿巴拉契亚这个僻静的角落里。

In the Inuit communities, scientists had pinpointed the problem, a deficiency of an enzyme that converted methemoglobin to hemoglobin. Studying the problem, Cawein figured out that he could convert methemoglobin to hemoglobin without the enzyme. All he needed was a substance that could "donate" a free electron to the methemoglobin, allowing it to bond with oxygen.

在因纽特人社区，科学家们已经确定了问题所在，即缺乏一种将高铁血红蛋白转化为血红蛋白的酶。通过研究这个问题，Cawein发现他可以在没有酶的情况下将高铁血红蛋白转化为血红蛋白。他所需要的只是一种物质，可以“捐赠”一个自由电子给高铁血红蛋白，使其与氧气结合。

The solution, oddly enough, was a commonly used dye called methylene blue. He injected the Ritchie siblings with 100 milligrams of the blue dye and didn't have to wait long to see results.

奇怪的是，这种溶液是一种常用的染料，叫做亚甲基蓝。他给里奇兄弟姐妹注射了100毫克的蓝色染料，没等多久就看到结果了。

"Within a few minutes. the blue color was gone from their skin," Cawein said. "For the first time in their lives, they were pink. They were delighted."

“几分钟之内。他们皮肤上的蓝色消失了，”Cawein说。“这是他们一生中第一次变成粉红色。他们很高兴。”

4.What Happened to the Blue People? 蓝种人身上发生了什么?

When young people started moving away from the farms surrounding Troublesome Creek in the mid-20th century, they took their recessive blue genes with them. Over time, fewer and fewer babies were born blue, and those who were took a methylene blue pill once a day to put the pink back in their cheeks.

20世纪中期，当年轻人开始搬离Troublesome Creek周围的农场时，他们带走了自己隐性的蓝色基因。随着时间的推移，越来越少的婴儿出生时是蓝色的，那些每天服用一次亚甲蓝药丸的婴儿的脸颊上又恢复了粉红色。

There are other ways to get blue skin without inheriting it, though. Methemoglobinemia can also be caused by reactions to certain topical pain relievers like benzocaine and xylocaine. And at least in one famous case, a man turned his skin permanently blue from drinking too much colloidal silver supplements and rubbing colloidal silver cream on his skin (the condition is called argyria or silver poisoning).

不过，还有其他方法可以在不遗传的情况下获得蓝色皮肤。高铁血红蛋白血症也可由对某些局部止痛药如苯佐卡因和多卡因的反应引起。至少在一个著名的案例中，一名男子因为喝了太多的胶体银补充剂，并在皮肤上摩擦胶体银霜，皮肤变成了永久的蓝色(这种情况被称为银中毒或银中毒)。

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