TED2016
Jennifer Kahn: Gene editing can now change an entire species -- forever
珍妮弗·卡恩: 基因剪辑现在可以永远改变整个种群
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CRISPR基因驱动装置允许科学家改变DNA序列，并确保编辑后性状可以遗传，开辟永远改变整个物种的可能性。更重要的是，该技术引发了新的问题：这项强大的新技术将如何影响人类？我们要使用它来改变什么？我们要扮演上帝的角色吗？聆听记者珍妮弗·卡恩在演讲中对这些问题的思考，同时与我们分享了基因驱动装置潜在的强大应用：打造能够根除疟疾和寨卡病毒的抗病蚊子。
Jennifer Kahn - Science journalist
In articles that span the gene-editing abilities of CRISPR, the roots of psychopathic behavior in children, and much more, Jennifer Kahn weaves gripping stories from unlikely sources. Full bio
In articles that span the gene-editing abilities of CRISPR, the roots of psychopathic behavior in children, and much more, Jennifer Kahn weaves gripping stories from unlikely sources. Full bio
Double-click the English transcript below to play the video.
00:12
So this is a talk about gene drives,
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这是一个有关于基因驱动的演讲，
但首先我先讲一个小故事。
00:15
but I'm going to start
by telling you a brief story.
by telling you a brief story.
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00:18
20 years ago, a biologist
named Anthony James
named Anthony James
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20年前，一位名为安东尼·詹姆斯的
生物学家正致力于培育不会传播
00:21
got obsessed with the idea
of making mosquitos
of making mosquitos
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疟疾的蚊子。
00:24
that didn't transmit malaria.
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00:27
It was a great idea,
and pretty much a complete failure.
and pretty much a complete failure.
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想法很好，但是结果是失败的。
00:32
For one thing, it turned out
to be really hard
to be really hard
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首先，让蚊子不携带疟疾
是非常困难的。
00:35
to make a malaria-resistant mosquito.
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00:38
James managed it, finally,
just a few years ago,
just a few years ago,
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最终，詹姆斯在几年之前
利用添加基因的方式才使
00:41
by adding some genes
that make it impossible
that make it impossible
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蚊子抵抗疟原虫的寄生成为可能。
00:44
for the malaria parasite
to survive inside the mosquito.
to survive inside the mosquito.
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00:47
But that just created another problem.
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但是接下来还有一个问题。
00:50
Now that you've got
a malaria-resistant mosquito,
a malaria-resistant mosquito,
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我们有了抵抗疟疾的蚊子，
要如何替换那些携带疟疾的蚊子呢？
00:52
how do you get it to replace
all the malaria-carrying mosquitos?
all the malaria-carrying mosquitos?
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00:58
There are a couple options,
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有很多方案，
方案一主要依靠培育的办法，
00:59
but plan A was basically to breed up
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向大自然中释放一群新型的
01:01
a bunch of the new
genetically-engineered mosquitos
genetically-engineered mosquitos
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经过基因改造的蚊子，
01:04
release them into the wild
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寄希望于它们大量繁殖，
稀释原来的基因。
稀释原来的基因。
01:06
and hope that they pass on their genes.
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01:08
The problem was that you'd have to release
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可是问题在于差不多要释放
10倍于原来蚊子数量的
转基因蚊子才有效果。
转基因蚊子才有效果。
01:10
literally 10 times the number
of native mosquitos to work.
of native mosquitos to work.
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如果一个小镇上有一万只蚊子，
01:15
So in a village with 10,000 mosquitos,
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就要释放十万只转基因蚊子。
01:17
you release an extra 100,000.
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01:20
As you might guess,
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可以想象
小镇村民肯定不会接受这个方案。
01:21
this was not a very popular strategy
with the villagers.
with the villagers.
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（笑声）
01:24
(Laughter)
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01:26
Then, last January,
Anthony James got an email
Anthony James got an email
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后来，今年一月的时候，
安东尼詹姆斯收到了一封来自于
安东尼詹姆斯收到了一封来自于
一名叫伊森比尔的生物学家的邮件。
01:30
from a biologist named Ethan Bier.
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01:33
Bier said that he
and his grad student Valentino Gantz
and his grad student Valentino Gantz
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比尔说他和他的研究生瓦伦蒂诺·甘茨
无意中发现了一种工具，
01:36
had stumbled on a tool
that could not only guarantee
that could not only guarantee
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不仅可以保证特定的基因会被遗传，
01:39
that a particular genetic trait
would be inherited,
would be inherited,
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而且基因传播的速度难以置信的快。
01:41
but that it would spread
incredibly quickly.
incredibly quickly.
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01:44
If they were right,
it would basically solve the problem
it would basically solve the problem
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如果他们是对的，
就从基本上解决了这个
就从基本上解决了这个
詹姆斯潜心研究20年的问题。
01:47
that he and James had been
working on for 20 years.
working on for 20 years.
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01:50
As a test, they engineered two mosquitos
to carry the anti-malaria gene
to carry the anti-malaria gene
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实验中需要两只携带抗疟疾基因的蚊子，
以及新的工具，即基因驱动装置，
01:55
and also this new tool, a gene drive,
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一会儿我会详细介绍。
01:57
which I'll explain in a minute.
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01:59
Finally, they set it up
so that any mosquitos
so that any mosquitos
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实验的设计是任何携带
抗疟疾基因的蚊子
02:01
that had inherited the anti-malaria gene
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将拥有红色的眼睛，
而不是常见的白色眼睛。
而不是常见的白色眼睛。
02:03
wouldn't have the usual white eyes,
but would instead have red eyes.
but would instead have red eyes.
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02:08
That was pretty much just for convenience
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这只是为了更好的通过肉眼
就可以区分它们的基因携带情况。
02:10
so they could tell just at a glance
which was which.
which was which.
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02:14
So they took their two
anti-malarial, red-eyed mosquitos
anti-malarial, red-eyed mosquitos
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研究者把两只抗疟疾红眼蚊子
放入一个有30只普通白眼蚊子的盒子中，
02:16
and put them in a box
with 30 ordinary white-eyed ones,
with 30 ordinary white-eyed ones,
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让它们自由繁殖。
02:19
and let them breed.
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02:21
In two generations, those had produced
3,800 grandchildren.
3,800 grandchildren.
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两代繁殖之后，培养了3800个子二代。
02:26
That is not the surprising part.
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这并不是让人惊讶的部分。
02:28
This is the surprising part:
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下面才是惊人的部分：
如果一开始只有两只红眼蚊子，
02:30
given that you started
with just two red-eyed mosquitos
with just two red-eyed mosquitos
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三十只白眼蚊子，
02:33
and 30 white-eyed ones,
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它们自由繁殖的后代大多数应该是白眼。
02:34
you expect mostly white-eyed descendants.
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02:38
Instead, when James opened the box,
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然而当詹姆斯打开盒子，
3800只蚊子全部都是红眼。
02:41
all 3,800 mosquitos had red eyes.
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02:45
When I asked Ethan Bier about this moment,
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当我问伊森比尔这一时刻的感受时，
他太兴奋了，在电话里一直叫喊着。
02:47
he became so excited that he was literally
shouting into the phone.
shouting into the phone.
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02:51
That's because getting
only red-eyed mosquitos
only red-eyed mosquitos
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因为只得到了红色眼睛的蚊子
打破了生物学的绝对基本定律，
02:54
violates a rule that is the absolute
cornerstone of biology,
cornerstone of biology,
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孟德尔遗传学定律。
02:57
Mendelian genetics.
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02:58
I'll keep this quick,
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这部分我大概讲一下，
孟德尔遗传学认为
当雄性和雌性交配，
当雄性和雌性交配，
03:00
but Mendelian genetics
says when a male and a female mate,
says when a male and a female mate,
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它们的后代会遗传父母各一半的基因。
03:02
their baby inherits half
of its DNA from each parent.
of its DNA from each parent.
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所以如果本来蚊子的基因是aa
转基因蚊子的基因是aB，
转基因蚊子的基因是aB，
03:05
So if our original mosquito was aa
and our new mosquito is aB,
and our new mosquito is aB,
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B是抗疟疾基因，
03:09
where B is the anti-malarial gene,
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后代应该呈现下面四种基因组合：
03:11
the babies should come out
in four permutations:
in four permutations:
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aa aB aa Ba。
03:13
aa, aB, aa, Ba.
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03:16
Instead, with the new gene drive,
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然而使用了新的基因驱动之后，
它们全变成了aB型。
03:19
they all came out aB.
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03:21
Biologically, that shouldn't
even be possible.
even be possible.
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从生物的角度说这应该是不可能的。
到底发生了什么呢？
03:24
So what happened?
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03:26
The first thing that happened
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首先，
2012年一种叫做CRISPR的
基因修改工具进入了人们的视野。
基因修改工具进入了人们的视野。
03:28
was the arrival of a gene-editing tool
known as CRISPR in 2012.
known as CRISPR in 2012.
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03:32
Many of you have probably
heard about CRISPR,
heard about CRISPR,
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很多人可能听说过CRISPR，
简而言之CRISPR是一种允许研究者
03:34
so I'll just say briefly that CRISPR
is a tool that allows researchers
is a tool that allows researchers
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快速，精准，简单地修改基因的工具。
03:38
to edit genes very precisely,
easily and quickly.
easily and quickly.
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03:41
It does this by harnessing a mechanism
that already existed in bacteria.
that already existed in bacteria.
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这种工具利用了一种存在于细菌中的机制。
也就是一个扮演了DNA剪刀角色的
03:45
Basically, there's a protein
that acts like a scissors
that acts like a scissors
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蛋白质，
03:47
and cuts the DNA,
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在一个RNA分子的指示下
03:49
and there's an RNA molecule
that directs the scissors
that directs the scissors
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剪刀可以作用于任何目标基因组。
03:51
to any point on the genome you want.
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就像是一个基因文字处理系统。
03:53
The result is basically
a word processor for genes.
a word processor for genes.
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你可以取出整段基因，
再加入一个进行替换，
再加入一个进行替换，
03:56
You can take an entire gene
out, put one in,
out, put one in,
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甚至可以编辑基因中的单个碱基。
03:58
or even edit just a single
letter within a gene.
letter within a gene.
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04:01
And you can do it in nearly any species.
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这个工具几乎适用于所有物种。
04:05
OK, remember how I said that gene drives
originally had two problems?
originally had two problems?
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前面我提过基因驱动有两大难题。
04:09
The first was that it was hard
to engineer a mosquito
to engineer a mosquito
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首先是如何培育一只
抗疟疾的蚊子。
04:12
to be malaria-resistant.
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多亏了CRISPR，我们解决了这个难题。
04:14
That's basically gone now,
thanks to CRISPR.
thanks to CRISPR.
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04:17
But the other problem was logistical.
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但是第二个问题随之而来。
04:19
How do you get your trait to spread?
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如何让这个性状得以传播？
04:22
This is where it gets clever.
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这就是这个装置精巧的地方。
04:24
A couple years ago, a biologist
at Harvard named Kevin Esvelt
at Harvard named Kevin Esvelt
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几年前，哈佛大学的一名叫做
凯文·恩斯福尔特的生物学家
凯文·恩斯福尔特的生物学家
探究如果不仅仅在
04:28
wondered what would happen
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新基因中使用CRISPR，
在剪切复制机制中
在剪切复制机制中
04:29
if you made it so that
CRISPR inserted not only your new gene
CRISPR inserted not only your new gene
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也使用CRISPR，会发生什么情况。
04:33
but also the machinery
that does the cutting and pasting.
that does the cutting and pasting.
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04:37
In other words, what if CRISPR
also copied and pasted itself.
also copied and pasted itself.
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换言之，如果CRISPR
自己也进行复制粘贴会如何。
自己也进行复制粘贴会如何。
04:42
You'd end up with a perpetual
motion machine for gene editing.
motion machine for gene editing.
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我们就得到了永动的基因修改工具。
04:46
And that's exactly what happened.
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事实果真如此。
04:49
This CRISPR gene drive that Esvelt created
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恩斯福尔特创造的CRISPR基因驱动装置
不仅保证了性状的传播，
04:51
not only guarantees
that a trait will get passed on,
that a trait will get passed on,
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而且当它作用于生殖细胞的时候，
04:55
but if it's used in the germline cells,
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它会在每个个体的两条染色体上
04:58
it will automatically copy and paste
your new gene
your new gene
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自动复制粘贴新的基因。
05:00
into both chromosomes
of every single individual.
of every single individual.
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05:03
It's like a global search and replace,
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就像是全面检索并替换的功能，
用学术术语来说，
就是杂合子性状纯合化。
就是杂合子性状纯合化。
05:06
or in science terms, it makes
a heterozygous trait homozygous.
a heterozygous trait homozygous.
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05:11
So, what does this mean?
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那么这意味着什么呢？
首先，我们拥有了一个很强大，
05:13
For one thing, it means we have
a very powerful,
a very powerful,
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但同时也令人担忧的新工具。
05:16
but also somewhat alarming new tool.
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05:20
Up until now, the fact that gene drives
didn't work very well
didn't work very well
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目前为止，基因驱动还并不是很有效，
这反而让我们感到欣慰。
05:23
was actually kind of a relief.
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05:25
Normally when we mess around
with an organism's genes,
with an organism's genes,
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通常，当我们对
有机体的基因进行研究时，
有机体的基因进行研究时，
会研究一些进化中不太可能发生的改变。
05:28
we make that thing
less evolutionarily fit.
less evolutionarily fit.
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生物学家可以随心所欲培育变异果蝇，
05:30
So biologists can make
all the mutant fruit flies they want
all the mutant fruit flies they want
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根本不用担心任何后果。
05:33
without worrying about it.
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就算有些逃出了实验室，
也无法在自然界中存活和繁殖。
也无法在自然界中存活和繁殖。
05:34
If some escape, natural selection
just takes care of them.
just takes care of them.
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05:38
What's remarkable and powerful
and frightening about gene drives
and frightening about gene drives
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基因驱动的强大和可怕之处在于
这种情况不再是理所当然的了。
05:41
is that that will no longer be true.
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05:45
Assuming that your trait does not have
a big evolutionary handicap,
a big evolutionary handicap,
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想象新的性状并没有一个
像蚊子不会飞那样的
像蚊子不会飞那样的
05:48
like a mosquito that can't fly,
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很大的进化缺陷，
基于CRISPR的基因驱动将很快地
05:50
the CRISPR-based gene drive
will spread the change relentlessly
will spread the change relentlessly
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让每一个个体拥有这种性状。
05:54
until it is in every single individual
in the population.
in the population.
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05:59
Now, it isn't easy to make
a gene drive that works that well,
a gene drive that works that well,
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目前为止基因驱动技术还并不完善，
但是詹姆斯和恩斯福尔特相信
最终我们可以做到。
最终我们可以做到。
06:02
but James and Esvelt think that we can.
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06:05
The good news is that this opens
the door to some remarkable things.
the door to some remarkable things.
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好消息是它拥有美好的前景。
只要在1%的疟蚊身上使用
06:09
If you put an anti-malarial gene drive
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含有抗疟疾基因的基因驱动装置，
06:11
in just 1 percent of Anopheles mosquitoes,
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疟蚊就是传播疟疾的蚊子，
06:13
the species that transmits malaria,
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06:15
researchers estimate that it would spread
to the entire population in a year.
to the entire population in a year.
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研究者预测一年之内
所有疟蚊都会获得新的基因。
所有疟蚊都会获得新的基因。
06:20
So in a year, you could virtually
eliminate malaria.
eliminate malaria.
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所以一年之内就可以根除疟疾。
06:23
In practice, we're still a few years out
from being able to do that,
from being able to do that,
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实际上我们还需要几年时间来进行试验，
但是目前，每天仍有1000个孩子死于疟疾。
06:27
but still, a 1,000 children
a day die of malaria.
a day die of malaria.
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一年之内这个数字可能几乎下降为0。
06:30
In a year, that number
could be almost zero.
could be almost zero.
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06:32
The same goes for dengue fever,
chikungunya, yellow fever.
chikungunya, yellow fever.
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登革热、基孔肯雅热、黄热病
也可以同样被根除。
也可以同样被根除。
这项技术会越来越成熟。
06:37
And it gets better.
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06:39
Say you want to get rid
of an invasive species,
of an invasive species,
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如果你想根除入侵物种，
比如五大湖中的亚洲鲤鱼。
06:41
like get Asian carp
out of the Great Lakes.
out of the Great Lakes.
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06:44
All you have to do is release a gene drive
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只要使用基因驱动
让鱼群只能繁衍雄性后代。
06:46
that makes the fish produce
only male offspring.
only male offspring.
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06:49
In a few generations,
there'll be no females left, no more carp.
there'll be no females left, no more carp.
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几代之后没有了雌性鲤鱼，
鲤鱼种群就会随之消失。
鲤鱼种群就会随之消失。
理论上我们可以通过这个方式保护
06:53
In theory, this means we could restore
hundreds of native species
hundreds of native species
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上百种濒临灭绝的本地物种。
06:56
that have been pushed to the brink.
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06:59
OK, that's the good news,
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上面都是好的部分，
下面说说负面影响。
07:02
this is the bad news.
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07:05
Gene drives are so effective
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基因驱动的效率太高，
以至于不经意释放的样本都可能
在短时间内引起整个种群的
在短时间内引起整个种群的
07:07
that even an accidental release
could change an entire species,
could change an entire species,
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07:10
and often very quickly.
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巨大改变。
07:13
Anthony James took good precautions.
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詹姆斯做好了预防措施。
他在一个生物控制实验室繁殖蚊子，
07:15
He bred his mosquitos
in a bio-containment lab
in a bio-containment lab
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并且蚊子也并不是美国本土的种类，
07:17
and he also used a species
that's not native to the US
that's not native to the US
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所以就算蚊子逃跑了，
07:20
so that even if some did escape,
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也会因为没有办法交配而灭绝。
07:21
they'd just die off, there'd be nothing
for them to mate with.
for them to mate with.
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但是如果有一些携带
只繁殖雄性后代基因驱动的亚洲鲤鱼
只繁殖雄性后代基因驱动的亚洲鲤鱼
07:24
But it's also true that if a dozen
Asian carp with the all-male gene drive
Asian carp with the all-male gene drive
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偶然从五大湖被带回了亚洲，
07:28
accidentally got carried
from the Great Lakes back to Asia,
from the Great Lakes back to Asia,
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这可能会让整个亚洲鲤鱼种群灭绝。
07:32
they could potentially wipe out
the native Asian carp population.
the native Asian carp population.
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07:37
And that's not so unlikely,
given how connected our world is.
given how connected our world is.
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鉴于现在世界联系的紧密程度，
这是很有可能的。
这是很有可能的。
这也是为什么会出现物种入侵。
07:40
In fact, it's why we have
an invasive species problem.
an invasive species problem.
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07:43
And that's fish.
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这是鱼类的情况。
07:45
Things like mosquitos and fruit flies,
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而像蚊子和果蝇一类的生物，
它们经常漂洋过海，
07:48
there's literally no way to contain them.
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基本上是没有办法限制它们的。
07:50
They cross borders
and oceans all the time.
and oceans all the time.
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07:53
OK, the other piece of bad news
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另外一个坏消息，
基因驱动不一定被限制在
07:55
is that a gene drive
might not stay confined
might not stay confined
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我们所谓的靶物种上。
07:58
to what we call the target species.
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08:00
That's because of gene flow,
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这是源于基因流动，
基因流动意思是相似的物种
08:02
which is a fancy way of saying
that neighboring species
that neighboring species
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偶尔会彼此杂交。
08:04
sometimes interbreed.
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如果发生了杂交，
有可能基因驱动会穿过物种的限制，
有可能基因驱动会穿过物种的限制，
08:05
If that happens, it's possible
a gene drive could cross over,
a gene drive could cross over,
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比如亚洲鲤鱼可能会影响
其他的鲤鱼种类。
其他的鲤鱼种类。
08:09
like Asian carp could infect
some other kind of carp.
some other kind of carp.
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如果基因驱动只是改变了一个性状，
比如眼睛颜色，可能还好。
比如眼睛颜色，可能还好。
08:11
That's not so bad if your drive
just promotes a trait, like eye color.
just promotes a trait, like eye color.
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而实际上，近期很可能将会有
08:15
In fact, there's a decent
chance that we'll see
chance that we'll see
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大量奇怪的果蝇被培育出来。
08:17
a wave of very weird fruit flies
in the near future.
in the near future.
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08:21
But it could be a disaster
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不过如果基因驱动
被用于毁灭物种，可能会导致大的灾难。
08:22
if your drive is deigned
to eliminate the species entirely.
to eliminate the species entirely.
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08:26
The last worrisome thing
is that the technology to do this,
is that the technology to do this,
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更为可怕的是基因驱动的技术，
这种能够培育含有基因驱动的有机体的技术，
08:29
to genetically engineer an organism
and include a gene drive,
and include a gene drive,
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基本上在世界上
任何一个实验室都可以做到。
任何一个实验室都可以做到。
08:33
is something that basically any lab
in the world can do.
in the world can do.
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本科生就可以做到。
08:36
An undergraduate can do it.
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08:39
A talented high schooler
with some equipment can do it.
with some equipment can do it.
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甚至有天赋的高中生
在有设备的情况下都可以做到。
在有设备的情况下都可以做到。
08:44
Now, I'm guessing
that this sounds terrifying.
that this sounds terrifying.
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这就很可怕了。
08:47
(Laughter)
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（笑声）
有趣的是，几乎每一个
和我探讨基因驱动的科学家
和我探讨基因驱动的科学家
08:49
Interestingly though,
nearly every scientist I talk to
nearly every scientist I talk to
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都不认为基因驱动实际上那么可怕和危险。
08:52
seemed to think that gene drives were not
actually that frightening or dangerous.
actually that frightening or dangerous.
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一部分原因是他们相信科学家们
08:56
Partly because they believe
that scientists will be
that scientists will be
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使用这个技术时都会非常小心谨慎。
08:59
very cautious and responsible
about using them.
about using them.
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（笑声）
09:01
(Laughter)
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目前为止确实如此。
09:02
So far, that's been true.
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09:04
But gene drives also have
some actual limitations.
some actual limitations.
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不过基因驱动也有一些实际的限制。
首先它只能应用于有性生殖的物种。
09:07
So for one thing, they work
only in sexually reproducing species.
only in sexually reproducing species.
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09:10
So thank goodness, they can't be used
to engineer viruses or bacteria.
to engineer viruses or bacteria.
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所以谢天谢地，
它们并不能用在细菌和病毒的培育上。
它们并不能用在细菌和病毒的培育上。
其次，性状只有在不停繁衍下才会传播。
09:14
Also, the trait spreads
only with each successive generation.
only with each successive generation.
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所以只有在繁殖周期很短的物种中
09:17
So changing or eliminating a population
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09:19
is practical only if that species
has a fast reproductive cycle,
has a fast reproductive cycle,
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改变或者灭绝种群才是可能的。
比如昆虫或者类似于鼠类
或者鱼类的小型脊椎动物。
或者鱼类的小型脊椎动物。
09:22
like insects or maybe
small vertebrates like mice or fish.
small vertebrates like mice or fish.
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09:26
In elephants or people,
it would take centuries
it would take centuries
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对于大象或者人类，可能需要几百年，
改变的性状才可能传播的足够广。
09:28
for a trait to spread
widely enough to matter.
widely enough to matter.
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09:32
Also, even with CRISPR, it's not that easy
to engineer a truly devastating trait.
to engineer a truly devastating trait.
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另外，就算有CRISPR，想要制造一个真正
可以引发灭绝的性状也不是简单的事。
可以引发灭绝的性状也不是简单的事。
09:38
Say you wanted to make a fruit fly
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比如你想制造一种果蝇，
它们以普通水果为食，
而不是腐烂的水果，
而不是腐烂的水果，
09:39
that feeds on ordinary fruit
instead of rotting fruit,
instead of rotting fruit,
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打算以此摧毁美国的农业。
09:42
with the aim of sabotaging
American agriculture.
American agriculture.
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首先你要搞清楚，
09:45
First, you'd have to figure out
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哪个基因控制果蝇的择食，
09:46
which genes control
what the fly wants to eat,
what the fly wants to eat,
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这已经是很复杂的项目了。
09:49
which is already a very long
and complicated project.
and complicated project.
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09:52
Then you'd have to alter those genes
to change the fly's behavior
to change the fly's behavior
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接下来你要根据你的想法通过改变基因
去改变果蝇的习性，
09:55
to whatever you'd want it to be,
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这将是更加复杂的项目。
09:57
which is an even longer
and more complicated project.
and more complicated project.
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甚至可能压根儿没什么效果，
10:00
And it might not even work,
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因为基因对于行为的控制是非常复杂的。
10:01
because the genes
that control behavior are complex.
that control behavior are complex.
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所以如果你是一个恐怖分子，
10:04
So if you're a terrorist
and have to choose
and have to choose
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你会选择开始一个耗时多年的
10:06
between starting a grueling
basic research program
basic research program
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艰苦卓绝的也许还没有结果的实验，
10:08
that will require years of meticulous
lab work and still might not pan out,
lab work and still might not pan out,
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还是直接选择炸毁目的地？
10:12
or just blowing stuff up?
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多半是后者。
10:13
You'll probably choose the later.
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10:15
This is especially true
because at least in theory,
because at least in theory,
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而且至少在理论上，
制造一个逆转驱动装置也应该很简单。
10:17
it should be pretty easy
to build what's called a reversal drive.
to build what's called a reversal drive.
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这样就可以覆盖
第一个基因驱动进行的改变。
第一个基因驱动进行的改变。
10:21
That's one that basically overwrites
the change made by the first gene drive.
the change made by the first gene drive.
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所以如果你对于改变的结果不满意，
10:24
So if you don't like
the effects of a change,
the effects of a change,
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启动第二个装置取消改变，
10:27
you can just release a second drive
that will cancel it out,
that will cancel it out,
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至少理论上是可行的。
10:29
at least in theory.
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10:33
OK, so where does this leave us?
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那么这一切到底告诉了我们什么呢？
10:36
We now have the ability
to change entire species at will.
to change entire species at will.
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我们现在可以随意改变整个种群。
10:41
Should we?
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是这样么？
10:42
Are we gods now?
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我们扮演上帝的角色了么？
10:45
I'm not sure I'd say that.
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我不这么认为。
10:48
But I would say this:
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我想说的是：
10:50
first, some very smart people
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首先，很多睿智的人
10:52
are even now debating
how to regulate gene drives.
how to regulate gene drives.
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现在已经开始讨论如何规范基因驱动。
10:55
At the same time,
some other very smart people
some other very smart people
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与此同时另外一些聪明的人
开始制定安全保护措施，
10:58
are working hard to create safeguards,
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比如让基因驱动自我调控，
或者在经过几代之后逐渐消失。
或者在经过几代之后逐渐消失。
11:00
like gene drives that self-regulate
or peter out after a few generations.
or peter out after a few generations.
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11:04
That's great.
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这是很好的。
11:06
But this technology still requires
a conversation.
a conversation.
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但是这项技术仍然需要更多讨论。
11:10
And given the nature of gene drives,
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而且鉴于基因驱动的本质，
全球都应该参与到讨论之中。
11:11
that conversation has to be global.
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11:14
What if Kenya wants to use a drive
but Tanzania doesn't?
but Tanzania doesn't?
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如果肯尼亚想使用一个基因驱动
但坦桑尼亚不想怎么办？
但坦桑尼亚不想怎么办？
11:17
Who decides whether to release
a gene drive that can fly?
a gene drive that can fly?
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谁来决定可以广泛传播的基因驱动
什么时候释放？
什么时候释放？
11:22
I don't have the answer to that question.
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我不知道答案。
11:25
All we can do going forward, I think,
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接下来我们能做的
是实事求是的讨论利弊，
11:27
is talk honestly
about the risks and benefits
about the risks and benefits
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并且对我们做出的选择负责。
11:30
and take responsibility for our choices.
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11:33
By that I mean, not just the choice
to use a gene drive,
to use a gene drive,
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我的意思是，
不仅仅是选择使用基因驱动，
不仅仅是选择使用基因驱动，
也可以选择禁用它。
11:37
but also the choice not to use one.
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11:41
Humans have a tendency to assume
that the safest option
that the safest option
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人类倾向的最安全的方案
就是维持现状。
11:44
is to preserve the status quo.
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11:46
But that's not always the case.
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但是事实往往不一定如此。
11:49
Gene drives have risks,
and those need to be discussed,
and those need to be discussed,
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基因驱动确实有风险，也需要认真讨论，
但是疟疾现在每天都夺去1000个人的生命。
11:53
but malaria exists now
and kills 1,000 people a day.
and kills 1,000 people a day.
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11:56
To combat it, we spray pesticides
that do grave damage to other species,
that do grave damage to other species,
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为了对抗疟疾我们播撒了
对于其他物种，包括两栖类和鸟类
对于其他物种，包括两栖类和鸟类
都伤害巨大的杀虫剂。
12:00
including amphibians and birds.
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12:03
So when you hear about gene drives
in the coming months,
in the coming months,
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所以如果接下来的几个月
你听到了基因驱动，
你听到了基因驱动，
你们一定会听到的，
12:06
and trust me, you will
be hearing about them,
be hearing about them,
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请记住我说的话。
12:08
remember that.
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行动意味着风险，
12:10
It can be frightening to act,
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但是有时无动于衷更加致命。
12:12
but sometimes, not acting is worse.
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12:16
(Applause)
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（掌声）
Translated by Gu Yu
ABOUT THE SPEAKER
Jennifer Kahn - Science journalistIn articles that span the gene-editing abilities of CRISPR, the roots of psychopathic behavior in children, and much more, Jennifer Kahn weaves gripping stories from unlikely sources.
Why you should listen
Jennifer Kahn likes to seek out complex stories, with the goal of illuminating their nuances. She teaches in the magazine program at the UC Berkeley Graduate School of Journalism, and is a contributing writer for the New York Times Magazine; she has written features and cover stories for The New Yorker, National Geographic, Outside, Wired and many more.
Her work has appeared in the Best American Science Writing anthology series four times, most recently for the New Yorker story “A Cloud of Smoke,” a story on the complicated death of a policeman after 9/11.
Jennifer Kahn | Speaker | TED.com