Ed Yong: Suicidal wasps, zombie roaches and other parasite tales

翻译人员: Xiaoou Chen 校对人员: Ying Wang

A herd of wildebeests, a shoal of fish,

一群角马,一群鱼，

a flock of birds.

一群鸟。

Many animals gather in large groups

许多动物群居生活

that are among the most wonderful spectacles

那些都是大自然中

in the natural world.

最令人惊叹的奇观。

But why do these groups form?

但是为什么形成这些群落？

The common answers include things like

通常的说法包括

seeking safety in numbers or hunting in packs

获得安全，或者方便捕猎

or gathering to mate or breed,

或者聚集交配繁殖，

and all of these explanations,

这些所有解释

while often true,

虽然通常正确

make a huge assumption about animal behavior,

但对动物行为做出了一个重要假设，

that the animals are in control of their own actions,

那就是动物掌控它们的行为，

that they are in charge of their bodies.

并掌控它们的身体。

And that is often not the case.

但是通常事实并不是这样。

This is Artemia, a brine shrimp.

这是卤虫，一种盐水虾。

You probably know it better as a sea monkey.

你们也许更通常地称它为海猴子。

It's small, and it typically lives alone,

它很小，典型的独居类型，

but it can gather in these large red swarms

但是它可以聚集在这些大的红色群落中

that span for meters,

其范围可达数米，

and these form because of a parasite.

这些的产生是因为一种寄生虫。

These shrimp are infected with a tapeworm.

这些虾子被一种绦虫寄生了。

A tapeworm is effectively a long, living gut

绦虫实际上是一条长长的活着的肠子

with genitals at one end and a hooked mouth at the other.

它一端是生殖器，另一端是钩状的嘴。

As a freelance journalist, I sympathize.

作为一个自由撰稿人，我对它感到同情。

(Laughter)

（笑声）

The tapeworm drains nutrients from Artemia's body,

绦虫从卤虫的体内摄取养分

but it also does other things.

但它也做别的事情

It castrates them,

它阉割卤虫,

it changes their color from transparent to bright red,

它将卤虫从透明变为赤红色,

it makes them live longer,

它延长卤虫的寿命,

and as biologist Nicolas Rode has found,

就像考古学家尼古拉斯·罗德所发现的

it makes them swim in groups.

绦虫让它们成群出没.

Why? Because the tapeworm, like many other parasites,

为什么呢？因为绦虫像很多别的寄生虫一样，

has a complicated life cycle

有着复杂的生命周期

involving many different hosts.

其中包括不同的寄主.

The shrimp are just one step on its journey.

这些虾子只是它们旅程中的一步.

Its ultimate destination is this,

它们最终的目标是

the greater flamingo.

更大的火烈鸟。

Only in a flamingo can the tapeworm reproduce,

绦虫只有在火烈鸟体内才可以繁殖，

so to get there, it manipulates its shrimp hosts

所以为了去那里，它操纵虾子寄主们

into forming these conspicuous colored swarms

形成这些显眼的有色群落

that are easier for a flamingo to spot

让火烈鸟更容去发现

and to devour,

并吞食。

and that is the secret of the Artemia swarm.

这就是卤虫群的秘密。

They aren't sociable through their own volition,

他们不是因为自身意志而聚集起来的，

but because they are being controlled.

而是因为被操纵。

It's not safety in numbers.

这不是用大数量去获得安全。

It's actually the exact opposite.

这恰恰相反。

The tapeworm hijacks their brains and their bodies,

这些绦虫劫持了卤虫们的大脑和身体，

turning them into vehicles

把它们变成交通工具

for getting itself into a flamingo.

以便于让它们进入到一只火烈鸟的体内。

And here is another example

这里有另外一个关于

of a parasitic manipulation.

寄生操控的例子.

This is a suicidal cricket.

这是一个自杀蟋蟀。

This cricket swallowed the larvae of a Gordian worm,

这只蟋蟀吞下了戈尔迪乌斯线虫

or horsehair worm.

或是马鬃虫的幼虫。

The worm grew to adult size within it,

虫子在蟋蟀体内长大成年，

but it needs to get into water in order to mate,

但是它需要到水中进行交配，

and it does that by releasing proteins

为了完成繁殖，它通过释放一种

that addle the cricket's brain,

扰乱蟋蟀大脑的蛋白质，

causing it to behave erratically.

使其行为不定。

When the cricket nears a body of water,

当蟋蟀靠近水体时，

such as this swimming pool,

例如这个游泳池，

it jumps in and drowns,

它会跳入，并溺死，

and the worm wriggles out

然后虫子从自杀蟋蟀尸体内

of its suicidal corpse.

蠕动出来。

Crickets are really roomy. Who knew?

蟋蟀总是胸怀宽广。谁知道呢？

The tapeworm and the Gordian worm are not alone.

绦虫和毛细线虫并不孤单。

They are part of an entire cavalcade

它们是全部

of mind-controlling parasites,

专于暗中破坏，压倒寄主意志

of fungi, viruses, and worms and insects and more

操控真菌，病毒，蠕虫，昆虫和更多其它生物的，

that all specialize in subverting and overriding

寄生虫

the wills of their hosts.

中的一部分。

Now, I first learned about this way of life

在二十年前

through David Attenborough's "Trials of Life"

我通过大卫·阿滕伯勒的纪录片《生命的审判》

about 20 years ago,

首次了解到到关于这种生活方式，

and then later through a wonderful book called

之后通过我的朋友卡尔 基默写的

"Parasite Rex" by my friend Carl Zimmer.

一本叫做《寄生虫雷克斯》书的对其进一步了解。

And I've been writing about these creatures ever since.

从那时起我就一直在写关于这些生物。

Few topics in biology enthrall me more.

没有别的什么生物学话题能更让我着迷。

It's like the parasites have subverted my own brain.

这就像寄生虫已经颠覆了我的大脑。

Because after all, they are always compelling

因为毕竟，它们总是在控制

and they are delightfully macabre.

并且令人欣喜的毛骨肃然。

When you write about parasites,

当你描写寄生虫时，

your lexicon swells with phrases like

你的用词里充满了这样的短语，

"devoured alive" and "bursts out of its body."

”活活吞吃“和“从它的身体里炸出”。

(Laughter)

（笑声）

But there's more to it than that.

但是远远不止这些。

I'm a writer, and fellow writers in the audience

我是一个作家，观众席中的作家同伙们

will know that we love stories.

知道我们热爱故事。

Parasites invite us to resist the allure

寄生虫使我们去排斥

of obvious stories.

浅而易见的故事的诱惑。

Their world is one of plot twists

它们的世界充满着

and unexpected explanations.

扭曲的情节，和出人意料解释。

Why, for example,

举个例子，为什么

does this caterpillar

这只毛毛虫

start violently thrashing about

当另外一直昆虫靠近它时

when another insect gets close to it

开始剧烈地颤动

and those white cocoons that it seems

并且像那些白色茧的

to be standing guard over?

护卫一样？

Is it maybe protecting its siblings?

难道它在保护兄弟姐妹？

No.

不对。

This caterpillar was attacked

这只毛毛虫受到了一只其在体内产卵的

by a parasitic wasp which laid eggs inside it.

寄生蜂的攻击。

The eggs hatched and the young wasps

卵孵化后，幼蜂们

devoured the caterpillar alive

将其活活地吞吃

before bursting out of its body.

再冲破其身体出来。

See what I mean?

现在知道（我之前）什么意思了吧？

Now, the caterpillar didn't die.

但是，毛毛虫没有死。

Some of the wasps seemed to stay behind

有些马蜂们留了下来，

and controlled it into defending their siblings

并继续控制毛毛虫去保护它们

which are metamorphosing

正在变态到成虫过程中茧内的

into adults within those cocoons.

兄弟姐妹们。

This caterpillar is a head-banging zombie bodyguard

这只毛毛虫是一个保护着

defending the offspring

杀死它的生物的后代的

of the creature that killed it.

甩头僵尸保镖。

(Applause)

（掌声）

We have a lot to get through. I only have 13 minutes. (Laughter)

我们还有很多要说。我只有13分钟.（笑声）

Now, some of you are probably just

现在，你们中有些人大概正

desperately clawing for some solace

因为这样的一些

in the idea that these things are oddities

自然中的怪异的事物

of the natural world, that they are outliers,

和局外者，绝望地搜寻一些安慰

and that point of view is understandable,

这个观点是可以理解的，

because by their nature, parasites are quite small

因为，寄生虫体型微小

and they spend a lot of their time

并且很大一部分时间生活在

inside the bodies of other things.

在其他动物的体内。

They're easy to overlook,

它们容易被忽略，

but that doesn't mean that they aren't important.

但这不意味着它们不重要。

A few years back, a man called Kevin Lafferty

几年前，一个叫做凯文·拉弗蒂的人

took a group of scientists into three Californian estuaries

带领一组科学家前往三个加州的河口

and they pretty much weighed and dissected

它们基本上将所有发现的东西

and recorded everything they could find,

称重，解剖，并记录，

and what they found

他们所发现的是

were parasites in extreme abundance.

寄生虫的数量极为巨大。

Especially common were trematodes,

最常见的是吸虫，

tiny worms that specialize in castrating their hosts

它们是小小的蠕虫，专阉割它们寄主

like this unfortunate snail.

就像这只不幸的蜗牛。

Now, a single trematode is tiny, microscopic,

单单一条吸虫是小的，微观的

but collectively they weighed as much

但是它们集合起来

as all the fish in the estuaries

和河口中的鱼等重

and three to nine times more than all the birds.

并且是所有鸟重量的三至九倍。

And remember the Gordian worm that I showed you,

还记得我之前向你们展示的戈尔迪乌斯线虫，

the cricket thing?

和那个蟋蟀么？

One Japanese scientist called Takuya Sato

一位叫佐藤拓也的日本科学家

found that in one stream,

在一条溪流中发现,

these things drive so many crickets

这些条虫使这么多

and grasshoppers into the water

蟋蟀和蚱蜢淹死在水中

that the drowned insects

以至于为当地的鲤鱼

make up some 60 percent of the diet of local trout.

提供了百分之六十的日常饮食.

Manipulation is not an oddity.

操控不是一种异常的现象

It is a critical and common part

这是我们身边普遍

of the world around us,

并且至关重要的一部分,

and scientists have now found

科学家现在已近发现

hundreds of examples of such manipulators,

成百上千这样操控者的例子,

and more excitingly, they're starting to understand

更让人激动的是，他们开始去理解

exactly how these creatures control their hosts.

这些生物是具体是如何控制它们的寄主的。

And this is one of my favorite examples.

这我最喜欢的例子之一，

This is Ampulex compressa,

这是扁头泥蜂，

the emerald cockroach wasp,

翡翠蟑螂蜂，

and it is a truth universally acknowledged

载有受精卵的蟑螂蜂

that an emerald cockroach wasp in possession

肯定需要一只蟑螂

of some fertilized eggs

是一个

must be in want of a cockroach.

被普遍接受的事实。

When she finds one,

当蟑螂蜂找到一只蟑螂，

she stabs it with a stinger

她会用刺蛰蟑螂，

that is also a sense organ.

那根刺又是一个感觉器官。

This discovery came out three weeks ago.

这个发现三周前才出来。

She stabs it with a stinger that is a sense organ

她用具感觉器官的刺蛰蟑螂

equipped with small sensory bumps

这个器官上有着小的突起物

that allow her to feel the distinctive texture

可以让蟑螂蜂感觉到

of a roach's brain.

蟑螂大脑中不同的质地。

So like a person blindly rooting about in a bag,

就像一个人在袋子里盲目地乱摸，

she finds the brain, and she injects it with venom

蟑螂蜂找到蟑螂的大脑，将毒液注射到

into two very specific clusters of neurons.

两簇非常具体的神经元中。

Israeli scientists Frederic Libersat and Ram Gal

以色列科学家弗雷德里克拉波塞特和莱姆加尔

found that the venom is a very specific chemical weapon.

发现这个毒液是一种非常特别的化学武器。

It doesn't kill the roach, nor does it sedate it.

它不会杀死蟑螂，也不会让其昏昏欲睡。

The roach could walk away

蟑螂如果想的话

or fly or run if it chose to,

可以选择走开，飞走，或跑开，

but it doesn't choose to,

但是它没有选择这样做，

because the venom nixes its motivation to walk,

因为那个毒液使其丧失了走的意愿，

and only that.

只是那样。

The wasp basically un-checks the escape-from-danger box

蟑螂蜂大体上关闭了

in the roach's operating system,

蟑螂神经系统中逃避危险的本能，

allowing her to lead her helpless victim

让蟑螂蜂能够借助蟑螂的触角

back to her lair by its antennae

领着她无助的受害者回到她巢穴，

like a person walking a dog.

就像一个人遛狗一样。

And once there, she lays an egg on it,

蟑螂一到那里，蟑螂蜂就在其体内产一个卵，

egg hatches, devoured alive, bursts out of body,

卵孵化了，幼虫将蟑螂活生生吞吃，并从其身体中迸发出来，

yadda yadda yadda, you know the drill.

吧啦吧啦叭啦叭啦，你们知道的。

(Laughter) (Applause)

（笑声）（掌声）

Now I would argue that, once stung,

我认为，蟑螂一旦被刺

the cockroach isn't a roach anymore.

它就不再是一只蟑螂了。

It's more of an extension of the wasp,

它更像是蟑螂蜂的一个延伸体，

just like the cricket was an extension of the Gordian worm.

就像蟋蟀是戈尔迪乌斯线虫的延伸体一样。

These hosts won't get to survive or reproduce.

这些寄主们不能生还和繁殖。

They have as much control over their own fates

它们对命运的掌握

as my car.

就像我的车的命运被我掌握一样。

Once the parasites get in,

一旦寄生虫进入其体内，

the hosts don't get a say.

寄主就失去了发言权。

Now humans, of course,

当然人类对于操控

are no stranger to manipulation.

并不陌生。

We take drugs to shift the chemistries of our brains

我们用药物移动我们大脑中的化学物质

and to change our moods,

去改变我们的心情，

and what are arguments or advertising or big ideas

有什么辩论或者广告或者伟大的想法

if not an attempt to influence someone else's mind?

不企图去影响其他人的思想呢?

But our attempts at doing this

但是我们对其的尝试

are crude and blundering compared

和那些寄生虫天衣无缝的专一性相比

to the fine-grained specificity of the parasites.

是不成熟的。

Don Draper only wishes he was as elegant

唐德雷珀只是希望他可以像翠绿的蟑螂蜂

and precise as the emerald cockroach wasp.

一样优雅和精确。

Now, I think this is part of what makes parasites

我认为这是让寄生虫

so sinister and so compelling.

如此险恶并如此引人注意一部分原因。

We place such a premium on our free will

我们如此珍视我们的自由意志

and our independence

和独立

that the prospect of losing those qualities

以至于我们在不可见力下

to forces unseen

失去那些品质的可能性。

informs many of our deepest societal fears.

揭示了许多我们最深处的社会恐慌。

Orwellian dystopias and shadowy cabals

奥威尔反乌托邦作品，神出鬼没的阴谋组织

and mind-controlling supervillains --

和会大脑操控的超级恶棍--

these are tropes that fill our darkest fiction,

这些都是充斥着我们邪恶小说中的比喻，

but in nature, they happen all the time.

但是在自然中，它们无时无刻不在发生。

Which leads me to an obvious

这让我提出了一个明显

and disquieting question:

又令人不安的问题：

Are there dark, sinister parasites

除了美国国家安全局

that are influencing our behavior

还有没有邪恶的寄生虫

without us knowing about it,

在我们不知道的情况下

besides the NSA?

影响着我们的行为？

If there are any —

如果有的话--

(Laughter) (Applause)

（笑声）（掌声）

I've got a red dot on my forehead now, don't I?

现在估计有人想把我灭了吧？

(Laughter)

（笑声）

If there are any, this is a good candidate for them.

如果有，这是一个非常好的候选人。

This is Toxoplasma gondii, or Toxo, for short,

这是弓形虫，简称弓虫

because the terrifying creature

令人毛骨悚然的生物

always deserves a cute nickname.

总是值得有一个可爱的名字。

Toxo infects mammals,

弓虫会感染哺乳类动物，

a wide variety of mammals,

各种各样哺乳动物，

but it can only sexually reproduce in a cat.

但是它只可以在猫体内有性繁殖。

And scientists like Joanne Webster have shown that

像乔安妮 韦伯斯特这样的科学家已经证明了

if Toxo gets into a rat or a mouse,

如果弓虫进入到老鼠体内

it turns the rodent into a cat-seeking missile.

它会将这个捏齿类动物变成寻猫导弹。

If the infected rat smells the delightful odor

如果被感染的老鼠问到了美妙的

of cat piss,

猫尿的味道，

it runs towards the source of the smell

它就会跑向那气味的发源地

rather than the more sensible direction of away.

而不是聪明的逃跑。

The cat eats the rat. Toxo gets to have sex.

猫吃了老鼠。弓虫去交配。

It's a classic tale of Eat, Prey, Love.

这是饮食，猎物，和爱情之间的经典故事。（笑点在于：这三个词的发音与一本畅销小说《美食、祈祷和恋爱》相似）

(Laughter) (Applause)

（笑声）（掌声）

You're very charitable, generous people.

你们都是善良慷慨的人啊。

Hi, Elizabeth, I loved your talk.

嗨，伊丽莎白（《美食，祈祷和恋爱》的作者)，我很喜欢你的演讲。

How does the parasite control its host

寄生虫是怎样

in this way?

在这种方式下操纵其寄主的？

We don't really know.

我不真正了解。

We know that Toxo releases an enzyme

但我们知道弓虫释放一种酶

that makes dopamine, a substance involved

这种酶制造

in reward and motivation.

一种涉及奖励与动机的物质--多巴胺

We know it targets certain parts of a rodent's brain,

我们知道这种酶把老鼠大脑中特定的部分作为目标

including those involved in sexual arousal.

包括那些涉及性冲动部分。

But how those puzzle pieces fit together

但这些拼图的碎片是怎样拼在一起的

is not immediately clear.

现在还不是很清楚。

What is clear is that this thing

清楚的是，弓虫

is a single cell.

是单细胞生物。

This has no nervous system.

它没有神经系统。

It has no consciousness.

它没有意识。

It doesn't even have a body.

它甚至连一个身体都没有。

But it's manipulating a mammal?

但是它却在操控一只哺乳动物？

We are mammals.

我们都是哺乳动物。

We are more intelligent than a mere rat, to be sure,

毫无疑问，我们比老鼠更加智慧

but our brains have the same basic structure,

但是我们大脑有着相同的基础构造，

the same types of cells,

同类型的细胞，

the same chemicals running through them,

同样的在其中穿梭的化学物质，

and the same parasites.

以及同样的寄生虫。

Estimates vary a lot, but some figures suggest

（对其的）推测各不相同，但数据显示

that one in three people around the world

全世界三分之一的人

have Toxo in their brains.

大脑里有弓虫。

Now typically, this doesn't lead to any overt illness.

很典型的是，它们不会导致任何显性病症。

The parasite holds up in a dormant state

寄生虫在很长的一段时间里

for a long period of time.

保持休眠状态。

But there's some evidence that those people

但是有一些证据显示，

who are carriers score slightly differently

那些是寄生虫载体的人在性格调查问卷中

on personality questionnaires than other people,

和其他人得分略有不同，

that they have a slightly higher risk of car accidents,

他们有稍微高一些车祸风险，

and there's some evidence that people with schizophrenia

有些证据显示精神分裂症的人

are more likely to be infected.

更容易被感染。

Now, I think this evidence is still inconclusive,

我认为这个证据是没有什么结果的，

and even among Toxo researchers,

而且在弓虫的调查人员之间

opinion is divided as to whether the parasite

对于是否寄生虫真正影响我们的行为

is truly influencing our behavior.

存在着争议。

But given the widespread nature of such manipulations,

但鉴于这种操控的普遍性，

it would be completely implausible

人类作为唯一没有

for humans to be the only species

相同症状的物种

that weren't similarly affected.

是难以置信的。

And I think that this capacity to constantly

我认为这种能够颠覆

subvert our way of thinking about the world

我们对这个世界思想方式的能力

makes parasites amazing.

让寄生虫十分迷人。

They're constantly inviting us to look at the natural world sideways,

它们不停地使我们从侧面去看大自然

and to ask if the behaviors we're seeing,

并使我们去质疑所目睹的行为，

whether they're simple and obvious

无论它们是简单明了，

or baffling and puzzling,

还是令人费解的，

are not the results of individuals

是否不是我们我们按照自己意愿

acting through their own accord

去行动的结果，

but because they are being bent

而是因为它们被歪曲

to the control of something else.

进而去控制别的东西的结果。

And while that idea may be disquieting,

当这个想法令人不安时

and while parasites' habits may be very grisly,

当寄生虫的行为冷人毛骨悚然时，

I think that ability to surprise us

我想那个让我们惊讶的能力

makes them as wonderful and as charismatic

使它们像任何熊猫，蝴蝶，或是海豚

as any panda or butterfly or dolphin.

一样美好和有魅力。

At the end of "On the Origin of Species,"

在“关于物种起源”的结尾，

Charles Darwin writes about the grandeur of life,

查尔斯·达尔文写到了关于生命

and of endless forms most beautiful

的辉煌，和无尽的最美丽的

and most wonderful,

最美好的形态的辉煌。

and I like to think he could easily have been talking

我认为，他很有可能在说

about a tapeworm that makes shrimp sociable

让虾子社会化的绦虫，

or a wasp that takes cockroaches for walks.

或者是带着蟑螂散步的马蜂。

But perhaps, that's just a parasite talking.

但是，也许我所说的只是被寄生虫操控的结果罢了。

Thank you.

谢谢。

(Applause)

(掌声)