你体内的鱼（2014）

我们认为…这可以说是一种远古定律
We think that this is a really sort of ancient principle.
像这种折叠，是整个过程中的第一步，
It's this sort of folding that was one of the first steps to be
让原本相当简单的皮肤，能够让…
able to actually then go on and from a very simple skin
…许多不同的器官，从它内部发展出来
to something with lots of different organs developing within it.
一但这皮肤折叠的过程完成后，它可以被修改
Once the process of folding skin was in place, it could be modified
皮肤
鳞片
羽毛
乳腺
牙齿
好去制♥造♥各式各样的皮肤器官
to produce all kinds of skin organs.
从爬行类的鳞片…到鸟的羽毛
From a reptile's scale to a bird's feather
甚至是那个为哺乳类下了定义的特征…乳腺
and even that defining body feature of mammals, mammary glands.
而让人惊讶的是，所有这些皮肤器官的形成，
And what's surprising is the formation of all skin organs
都由一颗主基因所控制，称作"EDA"
is controlled by a single master gene, called EDA.
我们所知的EDA，它的重要工作有…像是控制…
EDA we know is very important for doing things like controlling
你毛发量的多寡
how hairy you are.
像是…在一个特定的区域，有多少毛发形成
Therefore, how many hairs you form in a particular area.
或是…你有多少牙齿
Or, how many teeth you have
还有…那些牙齿看起来会是什么样子
and what those teeth are going to look like.
看起来似乎形成的方式有些许不同…
It seems to be doing something slightly different in all
那些不同的器官，但本质上全部都是相同的
those different organs but it's absolutely essential in all of them.
这个基因扮演了决定性的角色，
在打造这些来自于皮肤内部…
This gene plays a crucial role in building all the vital structures
…并且相当重要的结构上
that originate within skin.
而你如果真的想见到，EDA的力量有多强大，
And if you really want to see just how powerful EDA is,
见见演员…麦可.贝里曼
meet actor Michael Berryman.
我最重要的问题是，呃…演"星舰迷航记"的感觉是什么？
So my big question was, er,what was it like to be on Star Trek?
简直太棒了！
It was fantastic!
我是第一个波利安人
I was the first Bolian.
-蓝皮肤的…？
-没错
Blue-skinned...? Yes.
我认为我们是…嗯，很棒的变种
I think we were, er,a wonderful mutation...
麦可经常在科幻电影中扮演怪物或是外星人
Michael often plays monsters and aliens in science-fiction movies.
呃，这位置很好
Er, this is excellent.
他患有一种罕见的EDA基因突变，
He suffers from a rare mutation in his EDA gene
那阻止了他的皮肤器官正常发育，
that stopped his skin organs from developing properly.
我从很小的时候就有了这个体认
I had the experiences at a very young age.
我开始了解，我的皮肤出了问题
I started realising I had issues with my skin.
比如说…呃…没有指甲
For instance, er, no fingernails.
我有两片指甲，一片这里，一片那里
I have two nails here,one here, one here,
一片这里，还有那里，其余的都没有完整生长
one here and one here,the rest are not fully developed.
有些区域看起来就像生肉一样，
There were areas that were just raw meat,
完全没有皮肤在上面
where there was no dermis on it at all.
但我同时也了解到就是…呃，我没有牙齿
But I also realised that I, er,well, I had no teeth,
我仅有的牙齿，必须要拔掉
the teeth that I had had to be removed,
我这辈子都戴着假牙
I've worn dentures my entire life.
这同时也在社交方面影响了我，因为我无法调节体热
It also affected me in the manner of which I cannot dissipate body heat,
-而这是相当严重的问题
-是的
which is absolutely huge. Yeah.
我是说，你可是演员，你生活在聚光灯下
I mean, you're an actor.You're under hot lights.
你怎么解决？你如何…？
What do you do, what are the...?
呃…演戏成为了我在职业上的第二个选择，
Well, erm, the acting came about secondary to my chosen profession,
我本来是要做餐饮，我本来…我有一间餐厅，
which was food and beverage, I was going to be... I had a restaurant,
我本来将要成为一位厨师，呃…
I was on my way to be a chef, erm...
我开始了解到…我的体温非常容易过热
I started to realise that I would overheat quite readily,
所以…要降低体温唯一的方法就是…
so the only way in which I could dissipate the body heat was
…物理方法，也就是说我会走进冷冻库…
actually physically, meaning I would go into a freezer that was
-温度是零下二十度…
-哇！
20 below zero... Wow!
…然后，进行缓慢的深呼吸
..and, and breathe slowly and deeply
好去…呃…冷却我肺里的血液
to, er, cool the blood in my lungs.
所以…汗腺、指尖和指甲、还有头发也是？
So, sweat glands, fingertips and nails, er, hair? Yes. As well.
-牙齿
-牙齿也是
Teeth. Er, teeth.
这些都是皮肤器官，所以你可以让大家了解
These are all skin organs,so you of all people understand
皮肤有多么重要
just how important skin is.
没错，如果它们是健康的我会很高兴
Yeah, er, yeah,I like it when it's healthy!
麦可的皮肤情况，证明了EDA在形塑你的身体上，
Michael's skin condition demonstrates the crucial role EDA has had
扮演了多重要的角色
in shaping our bodies.
当我们观察进化过程…
When we look at evolution,
我们没有从祖先们那里遗传到身体结构
we don't inherit structures from our ancestors.
我没有遗传到手肘…
I didn't inherit an elbow, you know,
…从我们在北极找到的鱼身上
from the fish we found up in the Arctic.
我们遗传到的是…发育过程…基因
What we inherit are the developmental processes, the genes,
有点像是产品制♥造♥过程，去制♥造♥那些器官
sort of the manufacturing processes,if you will, to build those organs.
而EDA在我们的进化历史中，占了很重要的一环
And EDA was a very important part of our evolutionary history.
从牙齿到头发，甚至是汗腺，EDA基因…
From teeth to hair, and even skin glands, the EDA gene helped
帮助形塑了我们爬行类祖先的身体
shape the bodies of our reptile ancestors.
随着每一次变化，它们变的愈来愈像哺乳类
And with every change they became more and more like mammals.
但那里还有一项最重要的变化，帮助了它们…
But there was one more critical change that helped complete
…完整的变身为哺乳类
the transition to mammals.
而那丰富了我们今日的生命，
And it enriches our lives today.
全新形态的耳朵
A new kind of ear.
哺乳类的听觉结构非常独特
The hearing anatomy of mammals is unique.
你在爬行类身上不会看到耳瓣
You won't find ear flaps on any reptile.
我们的耳朵极度的敏感，允许了我们…
Our ears are extremely sensitive,allowing us
接收来自远距离的声音
to pick up a wide range of sounds.
从高音的吱吱叫…
From high-pitched squeaks...
…到近距离的呼唤
..to low distance calls.
好的
OK.
而关于这不可思议敏感度的秘密，
And the secret of their incredible sensitivity
就藏在我们身体最微小的骨头之中
lies in the tiniest bones in our body.
这些是我们中耳里的三块骨头
These are the three bones of our middle ear.
所有的哺乳类，包括人类，
All mammals, including people,
在头盖骨中，都拥有这三块小骨头
have these three bones that sit inside the skull.
而它们的任务是…利用小小的杠杆系统，
And what they do is they form a little lever system that turns
将空气中的震动转换为声音，让我们的神经系统可以感知
the vibration of air into sound that our nervous system can perceive.
我们和所有的哺乳类，中耳里都有这三块骨头
We, like all mammals, have three of these bones in our middle ear
但爬行类只有一块
but reptiles only have one.
这两块额外的骨头…锤骨和砧骨
These two extra bones -the malleus and incus -
让我们可以将耳膜接收到的声音扩大…
enable us to amplify sounds that reach our eardrum...
这是其中一个原因，我们的听力比爬行类优秀许多
..which is one reason why our hearing is so much better than reptiles.
这呈献出了一个简单…同时也非凡的谜题
This presents us with a simple -yet extraordinary - puzzle.
我们拥有三块骨头的敏锐听力，是如何…
How did our acute sense of hearing,using three bones,
…从爬行类祖先…只有一块骨头进化出来的？
emerge from our reptilian ancestors who used only one?
将近两个世纪以来，科学家们对这个谜题着迷不已
For nearly two centuries,scientists have been fascinated by this mystery
而其中一位，是我以前的学生…凯伦.席尔斯
And one of them is my former student, Karen Sears.
好的，这里是灰短尾负鼠
So, these are the grey,short-tailed opossum.
它们成为实验室的研究对象已有几十年了
And they have been used in labs for a few decades
它们现在成为了很受欢迎的实验室成员
and are now becoming a much more popular lab organism.
它们非常可爱
They are very cute.
所以，负鼠…就像其他的有袋哺乳动物，
So, the opossums,like other marsupial mammals,
母亲在很早就生下宝宝，相较于我们所谓的…
the mother gives birth very early compared to what we would call
胎盘哺乳动物…像是我们，像是老鼠，像是狗，
placental mammals, things like us,like mice, like dogs.
这些小家伙，它们有一个半月大，已经相当大
Now these guys, you know,they're a month and a half old.They're pretty big.
当它们出生
When they're born,
它们爬到这里…然后贴上这些乳♥头♥
they crawl up here and attach to these nipples.
而它们在这个阶段…大小只有几毫米
And they're only a few millimetres in length at that stage.
它们几乎还处于发育中的胚胎阶段
They are almost at an embryonic stage of development.
大约同等于人类发育四十天的胚胎
About the equivalent of a human embryo at about 40 days of development,
所以它们没有后肢…
so they don't really have hind limbs.
它们没有毛发，它们完全没有听觉，在那个时候
They have no hair. They can't hear at all, at that point.
这些负鼠，在交♥配♥后两个星期就出生
These opossums are born just two weeks after mating.
而凯伦…可以观察它们的耳骨…在各阶段的形成过程…
And Karen can see how their ear bones form at each stage of development,
从初期胚胎到成鼠
from early embryo to adult.
为了要找到骨头，她将这些负鼠安乐死…
In order to find the bones,she euthanises the opossums...
…然后利用食肉甲虫的幼虫…清除掉组织
..and uses flesh-eating beetle larvae to strip away the tissue
…留下赤♥裸♥的骨头
and leave bare bones.
这些皮蠹虫，被世界各地的实验室和博物馆所使用
These dermestid beetles are used by labs and museums the world over.
它们需要约24小时的时间…来完成工作
It takes about 24 hours for them to complete their work
凯伦现在有了一系列的头骨，让她能够…
Karen is then left a series of skulls through which she can
追踪中耳骨的发展过程…从胚胎到成鼠
trace the development of the middle ear bones from embryo to adult.
而这些头盖骨…揭露了惊人的事，
And what the skulls reveal is astonishing.
让人♥大♥吃一惊的是…
So, what's really surprising is