2019-04-02 【补】

原文来源：The Economist 2019-4-5

Redesigning life

The promise and perils of synthetic biology

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For the past four billion years or so the only way for life on Earth to produce a sequence of dna—a gene—was by copying a sequence it already had to hand. Sometimes the gene would be
damaged or scrambled, the copying imperfect or undertaken re- peatedly. From that raw material arose the glories of natural se- lection. But beneath it all, gene begat gene.

That is no longer true. Now genes can be written from scratch and edited repeatedly, like text in a word processor. The ability to engineer living things which this provides represents a funda- mental change in the way humans interact with the planet’s life. It permits the manufacture of all manner of things which used to be hard, even impossible, to make: pharmaceuticals, fuels, fab- rics, foods and fragrances can all be built molecule by molecule. What cells do and what they can become is engineerable, too. Im- mune cells can be told to follow doctors’ orders; stem cells better coaxed to turn into new tissues; fertilised eggs programmed to grow into creatures quite unlike their parents.

The earliest stages of such “synthetic biology” are already changing many industrial processes, transforming medicine and beginning to reach into the consumer world (see Technology Quarterly). Progress may be slow, but with the help of new tools and a big dollop of machine learning, biological manufacturing could eventually yield truly cornucopian technologies. Build- ings may be grown from synthetic wood or cor-al. Mammoths produced from engineered ele- phant cells may yet stride across Siberia.

The scale of the potential changes seems hard to imagine. But look back through history, and humanity’s relations with the living world have seen three great transformations: the exploitation of fossil fuels, the globalisation of the world’s ecosystems after the European conquest of the Americas, and the domestication of crops and animals at the dawn of agriculture. All brought prosperity and progress, but with damaging side-effects. Synthetic biology promises similar transformation. To harness the promise and minimise the peril, it pays to learn the lessons of the past.

The new biology calls all in doubt
Start with the most recent of these previous shifts. Fossil fuels have enabled humans to drive remarkable economic expansion in the present using biological productivity from ages past, stored away in coal and oil. But much wilderness has been lost, and carbon atoms which last saw the atmosphere hundreds of millions of years ago have strengthened the planet’s greenhouse effect to a degree that may prove catastrophic. Here, synthetic bi- ology can do good. It is already being used to replace some pro- ducts made from petrochemicals; in time it could replace some fuels, too. This week Burger King introduced into some of its res- taurants a beefless Whopper that gets its meatiness from an en- gineered plant protein; such innovations could greatly ease a shift to less environmentally taxing diets. They could also be used to do more with less. Plants and their soil microbes could produce their own fertilisers and pesticides, ruminants less greenhouse gas—though to ensure that synthetic biology yields such laudable environmental goals will take public policy as well as the cues of the market.

The second example of biological change sweeping the world is the Columbian exchange, in which the 16th century’s newly global network of trade shuffled together the creatures of the New World and the Old. Horses, cattle and cotton were intro- duced to the Americas; maize, potatoes, chilli and tobacco to Eu- rope, Africa and Asia. The ecosystems in which humans live be- came globalised as never before, providing more productive agriculture all round, richer diets for many. But there were also disastrous consequences. Measles, smallpox and other patho- gens ran through the New World like a forest fire, claiming tens of millions of lives. The Europeans weaponised this catastrophe, conquering lands depleted and disordered by disease.

Synthetic biology could create such weapons by design: pathogens designed to weaken, to incapacitate or to kill, and per- haps also to limit themselves to particular types of target. There is real cause for concern here—but not for immediate alarm. For such weaponisation would, like the rest of cutting-edge synthet- ic biology, take highly skilled teams with significant resources. And armies already have lots of ways to flatten cities and kill peo- ple in large numbers. When it comes to mass destruction, a dis- ease is a poor substitute for a nuke. What’s more, today’s synthetic-biology community lives up to ideals of openness and public service better than many older fields. Maintained and nurtured, that cul- ture should serve as a powerful immune system against rogue elements.

The earliest biological transformation—do- mestication—produced what was hitherto the biggest change in how humans lived their lives. Haphazardly, then purposefully, humans bred cereals to be more bountiful, livestock to be more docile, dogs more obedient and cats more companionable (the last a partial success, at best). This allowed new densities of settlement and new forms of social organisation: the market, the city, the state. Humans domesticated themselves as well as their crops and ani- mals, creating space for the drudgery of subsistence agriculture and oppressive political hierarchies.

Synthetic biology will have a similar cascading effect, trans- forming humans’ relationships with each other and, potentially, their own biological nature. The ability to reprogram the embryo is, rightly, the site of most of today’s ethical concerns. In future, they may extend further; what should one make of people with the upper-body strength of gorillas, or minds impervious to sor- row? How humans may choose to change themselves biological- ly is hard to say; that some choices will be controversial is not.

Which leads to the main way in which this transformation differs from the three that came before. Their significance was discovered only in retrospect. This time, there will be foresight. It will not be perfect: there will certainly be unanticipated ef- fects. But synthetic biology will be driven by the pursuit of goals, both anticipated and desired. It will challenge the human capa- city for wisdom and foresight. It might defeat it. But carefully nurtured, it might also help expand it.

Notes

gene begat gene
beget：leads to, 引发导致
Ex：Violence begets violence.

Now genes can be written from scratch and edited repeatedly, like text in a word processor.

from scratch
without any previous preparation or knowledge 从头开始；从零开始
I learned German from scratch in six months.
我从零学起，六个月学会了德语。

这个比喻不错，就像是打字机中打出来的文字

pharmaceuticals, fuels, fabrics, foods and fragrances can all be built molecule by molecule.
synthetic biology可以影响的事物：医药品，香水

reach into the consumer world
会触及，也就是会影响到
EX: This big change will reach into virtually every aspect of our daily life.

biological manufacturing
等同于 synthetic biology

look back through history
回顾历史

All brought prosperity and progress, but with damaging side-effects.
所有这些带来了繁荣与进步，但是也伴随着破坏性的副作用
Ex：The speedy growth of GDP in my country has brought prosperity and progress, but also with some damaging side-effects

Synthetic biology promises similar transformation.

promise V.
to make sth seem likely to happen; to show signs of sth 使很可能；预示

A promises some thing. A很可能会发生什么事儿，很可能会变成什么样

To harness the promise and minimise the peril, it pays to learn the lessons of the past.
这里的promise名词，很可能获得成功的迹象。peril：serious danger。为了能够把握住希望的曙光同时将危害减至最低，去学习过去的经验教训一定会收获颇多。

drive remarkable economic expansion
也就是economic success

from ages past
在过去，别总是用in the past

biological change sweeping the world
横扫席卷了整个世界，说明变化是全球性的，很重大

the Columbian exchange

哥伦布交换（英语：Columbian Exchange），又称大交换（Grand Exchange），是一场东半球与西半球之间生物、农作物、人种（包括欧洲人，与非洲黑人）、文化、传染病、甚至思想观念的突发性交流。它是人类历史上的跨越种族的一件重要事件。1492年哥伦布首次航行到美洲大陆，是世纪性大规模航海的开始，也是旧大陆与新大陆之间联系的开始，引发各种生态上的巨大转变。历史学者艾弗瑞．克罗斯比（Alfred W. Crosby）在1972年出版的著作《哥伦布大交换》（The Columbian Exchange）中，首先提出这个观念。

shuffled together the creatures of the New World and the Old
shuffle是洗牌的意思，引申混在一块儿。这边shuffle together A and B = shuffle A and B together

For such weaponisation would, like the rest of cutting-edge synthetic biology, take highly skilled teams with significant resources.
for: 作为连词

(old-fashioned or literary) used to introduce the reason for sth mentioned in the previous statement 因为；由于
We listened eagerly,for he brought news of our families.
我们急不可待地听着，因为他带来了我们家人的消息。
I believed her—for surely she would not lie to me.
我相信她的话 —— 因为她肯定不会向我撒谎。

A take B，need，需要。武器化需要技艺高超的团队并且配备非比寻常的资源

flatten cities
用来描述war，荡平了城市

Haphazardly, then purposefully,
用得很好了，无计划地，然后又有计划地。三个词就表达出来了

Humans domesticated themselves as well as their crops and animals, creating space for the drudgery of subsistence agriculture and oppressive political hierarchies.
驯服；刚够温饱的农业；政治上的等级制度，高低贵贱

people with the upper-body strength of gorillas, or minds impervious to sorrow
用来描述猛男，有着大猩猩般地上身力量；impervious：不受影响的，不受悲伤情绪影响的思维，意思是这个人相当的冷静沉着，不受情绪影响。
Ex：He is a man with minds impervious to sorrow.