经济学人阅读｜扉页文章 The aliens among us

08.25｜经济学人阅读｜扉页文章 The aliens among us

经济学人The Economist是一份英国的英文新闻周报，分八个版本于每周五向全球发行，编辑部位于伦敦，创办于1843年9月。

经济学人是一本综合性新闻评论刊物，有商业、国家和地区、经济和金融、科学和技术五大类。其中文章文风紧凑且严谨，对语言精准运用，展现出一种克制的风趣幽默，常运用双关语调侃。

经济学人对于英语考试的重要性不言而喻，其文章常常出现在雅思托福、SAT、GRE、GMAT、考研英语、四六级、MTI和CATTI的阅读理解真题中。

今天羚羊君（公众：aa-acad）给大家分享的是经济学人2020年8月22日期刊中扉页文章的第一篇：The aliens among us。

这篇文章讲到了病毒的特征、种类及数量繁多，病毒对地球生物进化的作用，以及人类对病毒的研究和利用。

想要阅读往期内容，可以在公众号右下角点击"更多资讯-长文阅读"进入专栏。

01

The aliens among us

病毒在我们之中

HUMANS THINK of themselves as the world’s apex predators. Hence the silence of sabre-tooth tigers, the absence of moas from New Zealand and the long list of endangered megafauna. But SARS-CoV-2 shows how people can also end up as prey. Viruses have caused a litany of modern pandemics, from covid-19, to HIV/AIDS to the influenza outbreak in 1918-20, which killed many more people than the first world war. Before that, the colonisation of the Americas by Europeans was abetted—and perhaps made possible—by epidemics of smallpox, measles and influenza brought unwittingly by the invaders, which annihilated many of the original inhabitants.

人类认为自己是世界的顶级掠食者。 因而造成了剑齿虎的灭绝，新西兰的莫阿斯遗迹以及一长串濒危动植物的名单。但是SARS病毒也显示了如何让人类也变成猎物。病毒引起了一系列的现代流行病，从新冠病毒到艾滋病，再到造成的死亡人数比第一次世界大战还多的1918-20年的流感爆发。在此之前，入侵者不经意间带来的天花，麻疹和流行性感冒病也许使欧洲人在美洲的殖民成为了可能。因为这些疾病消灭了许多原住民。

02

The influence of viruses on life on Earth, though, goes far beyond the past and present tragedies of a single species, however pressing they seem. Though the study of viruses began as an investigation into what appeared to be a strange subset of pathogens, recent research puts them at the heart of an explanation of the strategies of genes, both selfish and otherwise.

Viruses are unimaginably varied and ubiquitous. And it is becoming clear just how much they have shaped the evolution of all organisms since the very beginnings of life. In this, they demonstrate the blind, pitiless power of natural selection at its most dramatic. And—for one group of brainy bipedal mammals that viruses helped create—they also present a heady mix of threat and opportunity.

病毒对地球生命的影响远远超出了过去，并呈现了仅影响单一物种的悲剧，无论它们看起来多么紧迫。 尽管人类对病毒的研究始于对似乎是病原体的奇怪物体的调查，但最近的研究使病毒成为解释基因结构的核心。

病毒种类繁多，无所不在。从生命的一开始，它们对所有生物进化的影响就变得越来越清晰。通过这种方式，他们以最戏剧化的方式展示了自然选择的随机且无情的力量。而且，对于病毒协助创造的一组大脑性双足哺乳动物而言，它们还带来了令人头疼的威胁和机遇。

03

As our essay in this week’s issue explains, viruses are best thought of as packages of genetic material that exploit another organism’s metabolism in order to reproduce. They are parasites of the purest kind: they borrow everything from the host except the genetic code that makes them what they are. They strip down life itself to the bare essentials of information and its replication. If the abundance of viruses is anything to go by, that is a very successful strategy indeed.

正如我们在本周的文章中所解释的那样，病毒被认为是利用另一生物的新陈代谢来繁殖的遗传物质包装。它们是最纯净的寄生虫：它们从宿主那里借用了一切，除了它们使自己成为遗传密码。病毒将本身简化为信息及复制信息的基本要素。如果人体的运行需要使用大量的病毒，那确实是一个非常成功的策略。

04

The world is teeming with them. One analysis of seawater found 200,000 different viral species, and it was not setting out to be comprehensive. Other research suggests that a single litre of seawater may contain more than 100bn virus particles, and a kilo of dried soil ten times that number. Altogether, according to calculations on the back of a very big envelope, the world might contain 1031 of the things—that is one followed by 31 zeros, far outnumbering all other forms of life on the planet.

世界一直与病毒同在。一项对海水的分析发现了200,000种不同的病毒种类，而且这个分析还不是全面的。其他的研究表明，每升海水中可能含有超过1000亿个病毒颗粒，而一公斤的干燥土壤中含有的病毒颗粒数则是海水的十倍。根据一个非常大的信封背面的病毒数量计算，世界可能包含的病毒数量为：在1031后面加31个零，这远远超过了地球上所有其他形式的生命数量。

05

As far as anyone can tell, viruses—often of many different sorts—have adapted to attack every organism that exists. One reason they are powerhouses of evolution is that they oversee a relentless and prodigious slaughter, mutating as they do so. This is particularly clear in the oceans, where a fifth of single-celled plankton are killed by viruses every day. Ecologically, this promotes diversity by scything down abundant species, thus making room for rarer ones. The more common an organism, the more likely it is that a local plague of viruses specialised to attack it will develop, and so keep it in check.

众所周知，病毒（通常为多种不同类型）已经适应攻击存在的每种生物。它们是进化的强大力量的原因之一，他们负责着无情而大范围的屠杀，生物因此而变异进化。这在海洋中尤其明显，那里每天有五分之一的单细胞浮游生物被病毒杀死。从生态上讲，这相当于通过减少数量多的物种来促进生物的多样性，为稀有物种腾出生存空间。有机体越常见，就越有可能发展出专门攻击它的病毒，因此应对本土瘟疫加以控制。

06

This propensity to cause plagues is also a powerful evolutionary stimulus for prey to develop defences, and these defences sometimes have wider consequences. For example, one explanation for why a cell may deliberately destroy itself is if its sacrifice lowers the viral load on closely related cells nearby. That way, its genes, copied in neighbouring cells, are more likely to survive. It so happens that such altruistic suicide is a prerequisite for cells to come together and form complex organisms, such as pea plants, mushrooms and human beings.

这种瘟疫的产生暴发也是猎物发展防御的强大进化动力，这些防御有时会产生更广泛的后果。例如，解释一个细胞会故意破坏自己的原因，因为它的牺牲会降低附近紧密相关的细胞的病毒载量。这样，其基因复制到邻近细胞中则更有存活可能。碰巧这种无私的自杀是细胞聚集在一起并形成复杂生物的先决条件，例如豌豆植物，蘑菇和人类。

07

The other reason viruses are engines of evolution is that they are transport mechanisms for genetic information. Some viral genomes end up integrated into the cells of their hosts, where they can be passed down to those organisms’ descendants. Between 8% and 25% of the human genome seems to have such viral origins. But the viruses themselves can in turn be hijacked, and their genes turned to new uses. For example, the ability of mammals to bear live young is a consequence of a viral gene being modified to permit the formation of placentas. And even human brains may owe their development in part to the movement within them of virus-like elements that create genetic differences between neurons within a single organism.

病毒是生物进化的引擎的另一个原因是，它们是遗传信息的传输机制。一些病毒基因组可以最终整合到其宿主的细胞中，然后可以传给这些生物的后代。人类基因组的8％至25％似乎具有这种病毒起源。但是病毒本身又可以被劫持，它们的基因也有新用途。例如，哺乳动物具有新生的能力是因为病毒基因被允许以形成在胎盘中。甚至人类大脑的发育也可能部分归因于病毒样元素在其中的运动，这些元素在单个生物体内的神经元之间产生了遗传差异。

08

Evolution’s most enthralling insight is that breathtaking complexity can emerge from the sustained, implacable and nihilistic competition within and between organisms. The fact that the blind watchmaker has equipped you with the capacity to read and understand these words is in part a response to the actions of swarms of tiny, attacking replicators that have been going on, probably, since life first emerged on Earth around 4bn years ago. It is a startling example of that principle in action—and viruses have not finished yet.

Humanity’s unique, virus-chiselled consciousness opens up new avenues to deal with the viral threat and to exploit it. This starts with the miracle of vaccination, which defends against a pathogenic attack before it is launched. Thanks to vaccines, smallpox is no more, having taken some 300m lives in the 20th century. Polio will one day surely follow. New research prompted by the covid-19 pandemic will enhance the power to examine the viral realm and the best responses to it that bodies can muster—taking the defence against viruses to a new level.

进化论最引人入胜的见解是，惊人的复杂性可能来自生物体内部和生物体之间持续的，无情的，虚无的竞争。盲人制表师为您提供了阅读和理解这些词语的能力，这一事实在一定程度上是对自从大约40亿年前生命首次出现于地球以来一直在发生的微小的攻击性复制者的行为的回应。这是该原则付诸实践的惊人例子，而且病毒至今还没有灭绝。

人类是独特的，人类以病毒为导向并加以利用，为应对病毒威胁开辟了新途径。这始于疫苗接种的奇迹，它使人体可以在疫苗注射之后防御病原体的侵袭。由于有了疫苗，在20世纪夺走了约3亿条生命的天花病毒不再存在。脊髓灰质炎也终有一天会消失。新冠疫情引发的新研究将增强对病毒领域的检查以及使人体可以获得最佳的反应能力，从而将对病毒的防御提高到一个新水平。

09

Another avenue for progress lies in the tools for manipulating organisms that will come from an understanding of viruses and the defences against them. Early versions of genetic engineering relied on restriction enzymes—molecular scissors with which bacteria cut up viral genes and which biotechnologists employ to move genes around. The latest iteration of biotechnology, gene editing letter by letter, which is known as CRISPR, makes use of a more precise antiviral mechanism.

The natural world is not kind. A virus-free existence is an impossibility so deeply unachievable that its desirability is meaningless. In any case, the marvellous diversity of life rests on viruses which, as much as they are a source of death, are also a source of richness and of change. Marvellous, too, is the prospect of a world where viruses become a source of new understanding for humans—and kill fewer of them than ever before.

研究取得进展的另一条途径是操纵生物体的工具，这些工具基于对病毒及其防御的理解。基因工程的早期研究依靠限制性内切酶，即分子剪刀，细菌用剪刀来切割病毒基因，而生物技术人员则用分子剪刀来移动基因。生物技术的最新迭代是逐字母进行基因编辑，即CRISPR，它利用了更精确的抗病毒机制。

自然世界是残酷的。无病毒是无法实现的，以至于消灭它的欲望是毫无意义的。无论如何，生命的奇妙多样性取决于病毒，尽管病毒既是死亡的根源，又是进化的源头。奇妙世界的前景也如此，病毒将成为人类新认识的源泉，并杀死比以往更少的病毒。

经济学人一般目录大纲：

The world this week：简单梳理本周的时事Leaders：社论，对本周热点事件进行评论Briefing：简报，对一个特定热点话题深度讨论Letter：读者来信，对往期文章的评论Sections：各大洲及中美英三国的本周热点事件报道Business：商业新闻Finances and economics：财经新闻Science and technology：科技新闻Books and arts：文化书籍，书评和文化现象讨论Economic and financial indicators：商业及财经指数

Buttonwood：金融专栏Schumpeter：商业专栏Bartleby：职场专栏Bagehot：英国专栏Charlemagne：欧洲专栏Lexington：美国专栏Banyan：亚洲专栏