美国国家公共电台 NPR--Black Death survivors gave descendants a genetic advantage — but with a cost

Black Death survivors¹ gave descendants a genetic³ advantage — but with a cost

Transcript⁴

A study shows that survivors of the bubonic plague, which lasted from 1346 to 1353, may have passed on the ability to survive other pandemics. (Aired on All Things Considered on Oct. 19. 2022.)

LEILA FADEL, HOST:

Nearly 700 years ago, one of the biggest pandemics ever swept the globe. And now a recent study suggests that outbreak of bubonic plague may have helped protect future generations against disease. NPR's Michaeleen Doucleff has this story on the Black Death.

MICHAELEEN DOUCLEFF, BYLINE⁵: In 1348, the bubonic plague arrived in London and hit the city extremely hard. Luis Barreiro is at the University of Chicago and is a co-author of the study. He says that so many people were dying so quickly that...

LUIS BARREIRO: There was no more place in the cemeteries⁶. So what happened is that the king at the time bought this piece of land, and they start digging it.

DOUCLEFF: This land turned into a mass grave with hundreds of bodies, some stacked five deep. In the end, the Black Death killed up to 50% of people in parts of Europe and the U.K. That's a mortality rate that's nearly 1,000 times larger than what we've had during COVID.

BARREIRO: And we just went through this pandemic, right?

DOUCLEFF: Yeah.

BARREIRO: And we all think that it was insane. And, like, it completely changed the world and our societies and all that, Now try to project - I mean, if it's even possible for you to try to project a scenario⁷ where 30-, 50% of the population dies.

DOUCLEFF: Barreiro is a human geneticist. And he wondered if the people in London who did survive the Black Death could have had some kind of advantage, perhaps something in their DNA⁸, like a mutation⁹ that protected them. So he and his colleagues did something that almost seems like wizardry. They extracted DNA from the bodies buried at this mass cemetery¹⁰ and also from the bodies buried before and after the plague.

BARREIRO: We just wanted to see if we were able to identify particular mutations that would protect them against the agent that caused the Black Death.

DOUCLEFF: Turns out they hit the jackpot. They identified not one but four mutations that likely gave surviving Londoners an advantage. And the advantage was big. One mutation gave people a 40% advantage in terms of survival against the plague.

David Enard is an evolutionary¹¹ biologist at the University of Arizona. He says that 40% is the biggest evolutionary advantage ever recorded in humans. And survivors, of course, passed on that advantage to their descendants.

DAVID ENARD: It's faster and stronger than anything we've seen before in the human genome. And it's really pushing the boundaries of what we thought was possible, so it is a pretty big deal.

DOUCLEFF: One of the mutations, in a gene² called ERAP2, likely helped people clear out the plague infection quickly because it amps up the inflammatory response against the pathogen. This mutation has stuck around in the human genome for centuries, likely because it helps people fight off many pathogens.

ENARD: It's been advantageous¹² to have them around for many other potential bacterial¹³ or even viral epidemics¹⁴.

DOUCLEFF: But this mutation also comes at a cost. Maria Avila Arcos is a paleogeneticist at the National Autonomous¹⁵ University of Mexico. She says the mutation increases a person's risk of autoimmune diseases such as Crohn's.

MARIA AVILA ARCOS: If your immune system is, like, super strong, then that can also lead to autoimmune diseases.

DOUCLEFF: But the study, she says, has a big limitation. The Black Death struck Asia and parts of Africa. This study only tells us about a very small population of people, essentially¹⁶ northern Europeans, which greatly limits the scope of the findings.

AVILA ARCOS: There might be way more mechanisms¹⁷. Like population could have had, like, way more cellular¹⁸ mechanisms to cope with this, like, devastating¹⁹ outbreak.

DOUCLEFF: And so the question is what other advantages might our genome have that could be helping²⁰ to protect us against pandemics?

Michaeleen Doucleff, NPR News.

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1 survivors   

幸存者，残存者，生还者( survivor的名词复数 )

参考例句：

• The survivors were adrift in a lifeboat for six days. 幸存者在救生艇上漂流了六天。
• survivors clinging to a raft 紧紧抓住救生筏的幸存者

2 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

3 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

4 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

5 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

6 cemeteries   

n.（非教堂的）墓地，公墓( cemetery的名词复数 )

参考例句：

• It's morbid to dwell on cemeteries and such like. 不厌其烦地谈论墓地以及诸如此类的事是一种病态。 来自《简明英汉词典》
• In other districts the proximity of cemeteries seemed to aggravate the disease. 在其它地区里，邻近墓地的地方，时疫大概都要严重些。 来自辞典例句

7 scenario   

n.剧本，脚本；概要

参考例句：

• But the birth scenario is not completely accurate.然而分娩脚本并非完全准确的。
• This is a totally different scenario.这是完全不同的剧本。

8 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

9 mutation   

n.变化，变异，转变

参考例句：

• People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
• So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。

10 cemetery   

n.坟墓，墓地，坟场

参考例句：

• He was buried in the cemetery.他被葬在公墓。
• His remains were interred in the cemetery.他的遗体葬在墓地。

11 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

12 advantageous   

adj.有利的；有帮助的

参考例句：

• Injections of vitamin C are obviously advantageous.注射维生素C显然是有利的。
• You're in a very advantageous position.你处于非常有利的地位。

13 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

14 epidemics   

n．流行病

参考例句：

• Reliance upon natural epidemics may be both time-consuming and misleading. 依靠天然的流行既浪费时间，又会引入歧途。
• The antibiotic epidemics usually start stop when the summer rainy season begins. 传染病通常会在夏天的雨季停止传播。

15 autonomous   

adj.自治的；独立的

参考例句：

• They proudly declared themselves part of a new autonomous province.他们自豪地宣布成为新自治省的一部分。
• This is a matter that comes within the jurisdiction of the autonomous region.这件事是属于自治区权限以内的事务。

16 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

17 mechanisms   

n.机械( mechanism的名词复数 )；机械装置；[生物学] 机制；机械作用

参考例句：

• The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
• He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》

18 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。

19 devastating   

adj.毁灭性的，令人震惊的，强有力的

参考例句：

• It is the most devastating storm in 20 years.这是20年来破坏性最大的风暴。
• Affairs do have a devastating effect on marriages.婚外情确实会对婚姻造成毁灭性的影响。

20 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。