你体内的鱼（2014）

如果你观察这些初期负鼠胚胎，你看到的是…
if you look at these early opossum embryos what you see is
实际上爬行类形式的耳朵…只有一块耳骨
essentially a reptilian-style ear with one ear bone.
那两块额外的中耳骨，它们出现在耳朵时…
Those two extra middle ear bones,they're going to be in the ear,
…是在成鼠的时候
in the adult.
它们是下颚的一部份
They are part of the jaw.
所以…在下颚和头盖骨之间的下颚关节，
And so, the jaw joint between the skull and the jaw
看起来就像是爬行类
really looks like that of a reptile.
然后，在它们出生之后，
Then, after they're born
随着它们长大，那些小骨头将会…
and while they're growing up,those little bones that are going to
成为哺乳类的中耳，从下颚分离
be the mammalian middle ear,disconnect from the jaw.
它们变得相对较小
They get relatively smaller
并移♥动♥到最后的位置，成为哺乳类形式的耳朵
and move up to their final position to become a mammal-like ear.
所以，你拥有现代爬行类的一块耳骨，
So, if you have modern reptiles with one ear bone,
你拥有现代哺乳类的三块耳骨
you have modern mammals with three ear bones.
我认为胚胎在这里做到的…可以说是…
I think what the embryos do is they almost provide
在这两端之间制♥造♥了一个连结
a link between those two.
所以，我们在负鼠身上看到的是，从它们出生…
So, what we see in the opossums is from the time they're born,
到长大为成鼠，它们几乎是呈献了…
through they're adult, they almost go through
…三亿年的演化过程…在它们的耳朵上
300 million years of evolution in terms of their ears.
我们怎么可能知道…我们用来听东西的骨头
How do we know that the bones we use to hear with
竟是来自爬行类用来吃东西的骨头？
came from the bones reptiles use to eat with?
这个了不起的转变…我们见到了
下颚骨变成耳骨的发展过程，
Well, this amazing transition we see in development from jaw bones to ear bones,
我们也在化石记录上见到，
we also see in the fossil record.
我们在这里的化石中见到…在南非
And we see it in fossils from here in South Africa.
如果我们观察这些原始的似哺乳爬行类，
And if we look at some of these primitive mammal-like reptiles,
我们可以看到在下颚处有和我们非常不同的地方，
we see something in the lower jaw that's very different from us.
因为它拥有的是，一块骨头在这里…连结着牙齿
Because what it has is one bone here, which carries the teeth
然后那里有一些其他的骨头，
and then there's a bunch of other bones
它们可说是一般正常大小，位在下颚的后方，
that are sort of moderately sized that sit at the back of the jaw.
它们来自下颚关节
They form the jaw joint itself.
然候将时间快转，你会开始看到像这样的生物，
As you go forward in time, what you start to see are creatures like this,
有着大块的骨头…
which have a larger bone
连结着牙齿，
that holds all the teeth
和较小的骨头，位在下颚后方…来自下颚关节
and ever smaller bones at the back of the jaw that form the jaw joint.
然后我们来到重点，
Then we hit a point.
当你深入观察这只生活在两亿年前的动物
When you get to animals that lived around 200 million years ago,
在最近的化石记录中，
more recent in the fossil record,
你会发现它们拥有全新形式的下颚关节
you find that they have formed a completely new jaw joint.
那是因为连结着牙齿的那块颚骨…
That's because the bone that holds the teeth had grown
长的太大，已经触碰到了头盖骨
so large it made contact with the skull
所以，经过了数百万年后，
那些形成于旧下颚关节的骨头…
So, over millions of years, bones that formed the old jaw joint
开始缩小
began to shrink.
最终…变成多余的累赘
And eventually became redundant.
但是累赘没有被抛弃，这些旧下颚骨…
But instead of being lost altogether,these old jaw bones were
被废物利用…赋予了新的角色
repurposed to take up a new role,
在耳朵里
in the ear.
要查出这个转变何时发生是很困难的
Finding out when that transition took place is difficult
因为这些微小的骨头…没有拴牢在头盖骨中，
because the tiny ear bones sit loose in the skull
它们很少和其余的身体一起被找到
and they are rarely found with the rest of the body.
但是最近，一个令人着迷的新发现…
But, recently, a fascinating discovery was made
出现在这世界的另一端，
in another part of the world...
…中国
..China.
其中一位领导这项研究的科学家，
One of the leading scientists involved in the study
是我的同事…骆泽喜，他的实验室就在我的隔壁
is my colleague, Zhe-Xi Luo, who works in a lab next door to mine.
骆泽喜…是不得了的解剖学家
So, Luo is a fabulous anatomist.
这是一个人…他了解牙齿的解剖学
Here's a guy who knows the anatomy of the teeth,
下颚的解剖学、耳朵的解剖学…
the anatomy of the jaws,the anatomy of the ears of reptiles
爬行类和哺乳类的…还有这星球上每一个人的…
and mammals as well as anybody on the planet.
此外，他还能够研究非常微小的样本
Furthermore, he's able to work with really tiny specimens.
当化石第一次在地上被看到的时候，我的朋友觉得…
When the fossil was first spotted in the field, my friend thought
那只是颗小圆石
it's just a pebble.
骆泽喜
芝加哥大学
他捡了起来，然后了解到…有一块骨头在那小石头中，
He picked it up and he realised there were bones in that pebble.
是块化石
It's a fossil.
经过更仔细的研究，我们发现那其实是哺乳类的头骨
After more detailed work, we know that it's actually a mammal skull.
而它连结上了所有哺乳动物的起源，
And it's related to the origin of all mammals.
他们将它取名，"吴氏巨颅兽"
They named it Hadrocodium.
利用3D打印机，骆泽喜打造出这块小头骨的放大复♥制♥品
Using a 3D printer, Luo built an enlarged replica of its tiny skull.
牙齿…和其他哺乳类一样具有牙尖
The teeth had cusps like other mammals.
但脱颖而出的…是它的下颚部
But it's the lower jaw that really stood out.
颚部关节…看起来和现代哺乳类极度的相似，
The jaw joint looked remarkably like that of modern mammals,
这表示了，那块爬行类的旧下颚骨…
which suggests that the old reptilian jaw bones were
以经不再被用来进食
no longer being used to eat with.
它们已成为耳朵的一部份
They had become part of the ear.
在下颚里面，有可以支撑住耳骨的结构，
On the inside of the jaw, there are structures to hold the ear bone.
这告诉我们，吴氏巨颅兽的耳骨…仍然连着颚骨
This shows us Hadrocodium's ear bones are still attached to the jaw.
但是连结程度非常小
But the attachment was minimal.
吴氏巨颅兽的耳骨…正走在完全脱离的路上，
Hadrocodium's ear bones were on their way to being completely separate.
所以，这只一亿九千五百万岁的生物，不比一个回形针大
So, this 195 million-year-old creature, no bigger than a paper clip
为我们今日拥有的听力，迈出了重要的一大步，
had taken a big step towards the kind of hearing we have today.
拥有特化过的牙齿…
Along with its specialised teeth
…和毛皮，吴氏巨颅兽…被认为是最早的哺乳动物之一
and fur coat, Hadrocodium is regarded as one of the earliest mammals.
还有一个最后的惊喜，
And there was a final surprise,
另外一个重要的哺乳类特征…在头盖骨里，
another important mammalian feature inside its skull.
我们起初认为，早期哺乳类的脑…是相对小很多的
We originally thought the early mammals' brain were a lot smaller.
但是吴氏巨颅兽真的让我们大吃一惊，
But Hadrocodium really surprised us.
它的脑非常的大
It has a huge brain.
事实上，它的脑相对于它身体的质量，要大了50%
In fact, its brain is 50% bigger relative to its body mass
这是前所未见的
than anything before it.
这就是为什么我们将它取名"吴氏巨颅兽"…
That's why we called the fossil Hadrocodium.
意思是…它有颗非常巨大的脑
It means it's got a great big brain.
问题是，
The question is,
为什么我们的祖先…在一开始会需要这么大的脑？
why would our ancestors have needed such a big brain in the first place?
毕竟，它们又不需要打造城市或是写莎士比亚
After all, they weren't building cities or writing Shakespeare.
一亿九千五百万年前，较大的脑帮助了它们…
195 million years ago,a big brain helped them
在危险的黑夜之中生存下来
to survive in a dangerous night-time world.
一种新型态的爬行类堀起
The rise of a new kind of reptile -
恐龙
the dinosaurs -
迫使早期哺乳类…成为了在夜晚活动的小生物
forced the early mammals to become tiny creatures of the night.
从嗅觉到听觉，还有胡须的触感，
From smelling to hearing, to touching with their whiskers,
大量感官信息需要处理，迫使它们的脑变大
processing so much sensory information caused their brains to grow.
它们在夜晚觅食，白天则躲在它们的地洞中
They hunted in the dark and hid in their burrows during the day.
它们之中有许多…维持着这样的生活方式
Many of them maintained that lifestyle
长达一亿三千万年
for over 130 million years.
直到恐龙被另外一次的大灭绝消灭，
Only when the dinosaurs were wiped out in yet another mass extinction
在六千五百万年前，哺乳类才真正的堀起…并繁盛
65 million years ago, could the mammals truly emerge and flourish.
所以，当恐龙消失后，
So, when the dinosaurs disappeared,
哺乳类那个时候…可以说是就地起飞了
that's when mammals really took off in a big way.
没有错
That's right.
它们抓住了机会，接收了额外的资源，
They took the opportunity with all the vacant niches.
空出来的土地，而它们从原本…
The empty spaces on the land surface and they stepped out from
在恐龙的脚下讨生活，
under the dinosaurs' footprints
开始繁盛…和多样化
and radiated and diversified.
毫无疑问的，我们不会在这里…
So, in a very real sense we wouldn't be here
如果不是恐龙的死亡和消失，对吗？
if it wasn't for the removal -or death - of the dinosaurs, right?
肯定是
Certainly.
我们最早的哺乳类祖先是个小家伙
Our earliest mammalian ancestors were tiny.
但是在它们身体之中…如同在我们之中
But deep within their bodies,just as in ours,
写着难以置信的历史
is an incredible history.
你观察化石愈多，你观察胚胎愈多，
The more you look at fossils,the more you look at embryos,
你就愈能了解，我们是回收利用的爬行类
the more you see that we're repurposed reptiles.
我用来说话的下巴，用来吃东西的牙齿…
The jaw I'm using to talk with,the teeth I use to eat with,
用来听东西的耳骨，皮肤和它上面的结构…
the ear bones I use to hear with,the skin and the structures that appear within it,
这些…来自我们的爬行动物过往
that arose,are in our reptile past.
所以，毫无疑问的，
So, in a very real sense,
每一天，我们体内的爬行动物，都深深影响着我们
every day we feel the consequences of our inner reptile.