60秒科学:城市生活增强感染性疾病抵抗力

The descendants of longtime urban dwellers¹ show increased genetically⁴ driven resistance to tuberculosis⁵, due to evolutionary⁶ selection pressure over millennia⁷. Christopher Intagliata reports

城市长久居住民的后代，经过数千年的自然选择，对结核病的抵抗力更强。

City living has obviously influenced human culture—as have often been noted⁸, how you gonna keep ‘em down on the farm after they’ve seen Paree'? But urban life may have also influenced human genes⁹, making the descendants of ancient city dwellers more resistant¹⁰ to disease. That's according to a study in the journal Evolution. [Ian Barnes et al., Ancient Urbanisation Predicts Genetic³ Resistance To Tuberculosis]

The researchers started from the premise¹¹ that densely¹² populated cities would be good places for infectious diseases, which could spread easily from person to person. That situation should have set up selection pressure for the ability to survive such infections.

The scientists sampled the DNA¹³ of 17 populations from Africa, Asia and Europe, including longtime urbanites—like Italians, Turks and Iranians—and traditionally rural or nomadic¹⁴ groups, like Malawians or the Saami people of northern Scandinavia.

Then the researchers zeroed in on a gene² variant¹⁵ that offers protection against diseases like tuberculosis or leprosy. After controlling for any shared ancestry¹⁶ between the groups, they indeed found that the protective gene was significantly more common in cultures with a long history of urban settlement. Which may be some comfort next time someone's sneezing near you on the subway.

—Christopher Intagliata
 

1 dwellers   

n.居民，居住者( dweller的名词复数 )

参考例句：

• City dwellers think country folk have provincial attitudes. 城里人以为乡下人思想迂腐。 来自《简明英汉词典》
• They have transformed themselves into permanent city dwellers. 他们已成为永久的城市居民。 来自《简明英汉词典》

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 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

5 tuberculosis   

n.结核病，肺结核

参考例句：

• People used to go to special health spring to recover from tuberculosis.人们常去温泉疗养胜地治疗肺结核。
• Tuberculosis is a curable disease.肺结核是一种可治愈的病。

6 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。

7 millennia   

n.一千年，千禧年

参考例句：

• For two millennia, exogamy was a major transgression for Jews. 两千年来，异族通婚一直是犹太人的一大禁忌。
• In the course of millennia, the dinosaurs died out. 在几千年的时间里，恐龙逐渐死绝了。

8 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

9 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

10 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

11 premise   

n.前提；v.提论，预述

参考例句：

• Let me premise my argument with a bit of history.让我引述一些史实作为我立论的前提。
• We can deduce a conclusion from the premise.我们可以从这个前提推出结论。

12 densely   

ad.密集地；浓厚地

参考例句：

• A grove of trees shadowed the house densely. 树丛把这幢房子遮蔽得很密实。
• We passed through miles of densely wooded country. 我们穿过好几英里茂密的林地。

13 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。

14 nomadic   

adj.流浪的；游牧的

参考例句：

• This tribe still live a nomadic life.这个民族仍然过着游牧生活。
• The plowing culture and the nomadic culture are two traditional principal cultures in China.农耕文化与游牧文化是我国传统的两大主体文化。

15 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

16 ancestry   

n.祖先，家世

参考例句：

• Their ancestry settled the land in 1856.他们的祖辈1856年在这块土地上定居下来。
• He is an American of French ancestry.他是法国血统的美国人。