你体内的鱼（2014）

but do the genes that shape our hands also shape these skate fins?
为了查明，蓝迪操控了灰鳐的胚胎，
To find out,Randy manipulated the skate embryos
就像克里夫对鸡胚胎做的一样，
like Cliff had done with the chick embryos.
他放了一颗装有音猬因子的小珠子，
He put a bead containing the Sonic Hedgehog molecule
…到成长中鳍芽的另外一侧
on the opposite side of a growing fin bud.
结果发现，音猬因子有效的…
And it turns out that Sonic Hedgehog was sufficient
导致了镜像副本的产生，
to cause a mirror-image duplication,
第二对鳍，形成在灰鳐身上
a second fin, to form in the skate.
这和音猬因子在克里夫的小鸡上…所发生的事一模一样，
This is exactly what Sonic Hedgehog had done in Cliff's chickens.
我们完全被震惊了，
We were absolutely stunned
你必须要记得，这个灰鳐胚胎，
and you have to remember that this is a skate embryo
所告诉我们的是…这个非常基本的机转模式
and what that tells us is that these very basic patterning mechanisms
达到了完全相同的功能…在灰鳐身上…
are performing the exact same functions in the skate,
在鲨鱼，在鸡，在老鼠的身上…
in the shark, in the chicken,in the mouse,
一直到人类的身上
all the way up to humans.
我们追踪音猬因子，
We had traced Sonic Hedgehog
一路回到了古老的海洋生命，
all the way back to life in ancient oceans.
那颗决定我们手部形状的基因…
A gene that determines the shape of our hands
也决定了一些与我们关系疏远的亲戚…鱼类鳍的形状
was also shaping the fins of some of our most distant fish relatives.
我们体内的鱼，深深影响我们
Our inner fish runs deep.
但仍旧有一个大谜题要解开
But there was still a big mystery go solve.
我们的鱼类祖先是如何过渡到陆地上的？
How did our fish ancestors make the transition onto land?
它们看起来是什么样子？
And what did they look like?
我们仍然在寻找那难以捉摸的化石
We were still looking for our elusive fossil,
一个被永远冰存起来的伟大过渡时刻
frozen for ever on the brink of this great transition.
每一个夏天，我们回到杰森的远古河床，
Each summer, we returned to Jason's ancient riverbed
继续我们的挖掘
to continue excavating.
我们必须清除许多的石头
We needed to move lots of rock
暴露出包含化石的狭窄缝隙，
to expose the narrow seam containing the fossils.
然后…我们换上刷子和牙科探针，
But then we'd switch to brushes and dental picks
揭开那美丽化石的面纱
to uncover the delicate fossilised bone.
这是难以置信的好笑
It's an incredibly funny paradox.
我们身在这片广大的景色之中，但我们永远挤成一团
We're in this huge landscape and we're always cramped together.
我的头靠着泰德的脚，马克的头靠着我的脚，
My head's next to Ted's feet.Mark's head's next to my feet.
在这一小块地方
It's this tiny little spot.
在这片广大景色中的一个小角落，
'It was in such a tiny corner of this vast landscape
我们终于发现了金矿
'that we finally struck gold.'
那是2004年7月的第二个星期，
It was the second week of July in 2004,
我们都在这个坑中工作，
we were all working in this hole
然后史帝夫说，"嘿，各位，这什么玩意？"
and Steve says,"Hey, guys, what's this?"
泰德和我跑过去…我们看到的是，
Ted and I go running over and what we saw...
是这个"V"的型状，被石头覆盖着，
..was this "V" here,it was covered with rock.
当我们看到了这个"V"，然后我们看到了底下的牙齿
And as soon as we saw this "V" and we saw these teeth under it,
这再明显不过了，我们看到的这个"V"型状…
it became very clear that this little "V" we're seeing
是口鼻部的尖端
is the tip of a snout
而那是一只平头鱼的口鼻部
and that this was a snout of a flat-headed fish.
我们在这里停了下来，
'We stopped in our tracks.
平头结构，是过渡鱼类的可能特征
'A flat head was a likely sign of a transitional fish.'
这就是我们在寻找的生物该有的口鼻部，
Here was the snout of exactly the creature we were looking for
而这从石头中露了出来，
sticking out of the rocks.
所以如果我们幸运的话，
So if we had any luck whatsoever,
其余的部位应该会藏在石头之中
the rest of the creature would be encased in the rock.
所以我们沿着化石周围不断的挖掘…
'So we dug all the way around the fossil,
移开巨大的石头，然后我们注入石膏
'leaving a chunk of rock that we then encased in plaster.
我们等不及见到里面会是什么
'We couldn't wait to see what was inside.'
当我们回到家，我知道我们有了平头鱼，
OK, we get home.We knew we had a flat-headed fish,
但是我们拥有多少？
but how much of it did we have?
然后标本制♥作♥师接手，
Then the preparators take over.
他们移除了石膏外层，然后他们做的第一件事…
They removed the plaster jackets and the first thing they did
就是侵蚀石头，让口鼻部暴露出来
was etch away at the rock, exposing the front part of the snout.
大约过了一个半月，
About a month-and-a-half goes by
他们开始发现了眼眶…眼洞…
and they start to find the orbits,the eye holes.
然后我们看到了肩部，然后我们看到了鳍
And then we see the shoulder and then we see the fins
然后我们看到愈来愈多
and then we see more and more
直到我们几乎看到了完整的身体上部
until we see pretty much the entire topside of the body.
最棒的地方在于，我们有这颗头连结着身体…
What's really wonderful is that we have the head connected to a body
然后身体连结着鳍，
and the body connected to the fins,
所以我们知道这片鳍是来自于这只动物，
so we know that this fin comes from this animal
我们也知道它的尺寸，和它们是如何连结在一起的
and we know its size and how it fits together.
之后，我们又找到其他的部份化石，
Later we found parts of other specimens
这个生物相当大，有九呎长，
and some of these were really big,up to nine feet long.
当地的因纽特人，把我们的化石取名叫"提塔利克鱼"
The local Inuit people named our fossil "Tiktaalik",
意思是，"大淡水鱼"
which means "large freshwater fish."
当我们整理我们的发现时，
And as we took stock of our discovery,
真正刺♥激♥的开始了
the real excitement began.
这是达尔文曾预言会存在的生物
Here was an animal Darwin had predicted,
真正的混合结构
a real anatomical mixture
它拥有一些鱼的特征，像是鳞片、鳍和鳃
It had some features of fish,like scales and fins and gills.
它同时也拥有肺来呼吸空气
It also had lungs for breathing air.
而且，让我们震惊的是，它有脖子
And, to our astonishment,it had a neck,
和我们一样的最早期生物，以前从未发现过
the earliest one like ours ever found.
但在鳍的内部藏着关键，我们看到了欧文的早期研究…
But inside the fins lie the clincher - we see an early version of Owen's
一根骨头、两根骨头、很多小骨头的模式
"one bone, two bones,lots of bones" pattern
就和我们今日肢体的模式相同
that we see in our own limbs today.
它甚至还有腕关节
It even had a kind of wrist,
这是第一个可和人手连结起来的特征
the first signs of a link to the human hand.
每一次你弯曲你的手腕，或是转动你的头，
Every time you flex your wrist or shake your head,
你都要感激提塔利克鱼，你的泥盆纪表亲…
you can thank Tiktaalik and its Devonian cousins
在这远谷的溪流中，适应了生命
adapting to life in these ancient streams.
不像其他的鱼，提塔利克鱼可以使用它的脖子，
Unlike other fish,Tiktaalik could use its neck
去注意掠食者，
to watch out for predators
并猎捕小型的猎物，
and to hunt smaller prey.
而且因为那些鳍够强壮，
And because those fins were strong enough
可以将它的身体抬离水面，
to lift its body out of the water,
一扇全新的大门敞开了，
a whole new frontier opened.
几百万年后，提塔利克鱼的那两对类鱼鳍，
Over millions of years, the two pairs of fins in fish-like Tiktaalik
将会转变为两对肢体…
would lead to the two pairs of limbs
到地球上所有的骨骼动物身上
in every bony animal on Earth.
这是了不起的遗产，今日能在我们的双手双脚上看到，
It's a powerful legacy we can see in our own arms and legs today.
要了解提塔利克鱼，想一想俯卧撑吧
Well, to think about Tiktaalik,think about a push-up.
我们在做俯卧撑的时候做了什么？
What are we doing when we do a push-up?
我们使用了连结在我们胸部上的肌肉，
We're using the muscles that attach to our chest
然后经由我们下方的手臂，给我们力量把身体撑起来
and to the underside of our arm to give us the power to raise up.
我们使用了手肘…和可弯曲的手腕，
We use our elbows and use flexion at the wrist,
而这相当重要，因为这让我们的手掌得以接触地面，
which is important because it allows our palm to contact the ground.
这是提塔利克鱼的鳍，有什么特色？
Here's the fin of Tiktaalik,And what does it have?
它有很大的表面♥积♥，让肌肉得以连结…
It has a massive surface for a connection of muscles
能够将肩部和上肢内侧连结在一起，
that would attach the shoulder to the underside of the upper arm.
它还具有高度活动性的肘关节，
It has evidence of a highly mobile elbow
甚至还有可弯曲的腕部
and it even has a wrist that can flex
而这让它的掌心…能够接触地面，
so that the equivalent of the palm can contact the ground.
这是一只可以做俯卧撑的鱼
Here's a fish that can do a push-up.
我还记得第一次看到提塔利克鱼腕关节的时候，
I remember looking at the wrist of Tiktaalik for the first time
那个当下，我有了和在解剖室里同样的感觉，
and at that moment, I felt akin to what I felt in the anatomy lab
当我看到尸体和他的手时
when I saw the cadaver and its hand.
手实际上以很多种方式定义了我们
The hand actually defines us in many ways.
当你想想，是什么让人类如此独一无二，
When you think about what makes our species unique and special,
我们有想法，并有能力去实现那些想法，
it's having thoughts and being able to make those thoughts real.
而实现那些想法，依靠的是我们的双手
And the way our thoughts become real is through use of our hands -
去打造东西，去制♥造♥东西
to build things, to make things.
而这美妙且复杂的基本形状，
Yet the basic form of this wonderfully complex,
一部份的人类标准结构，
quintessentially human piece of anatomy
可以一路回溯到远古鱼类的鳍，
can be traced back to the fins of ancient fish.
这是一个难以置信的演化故事，现在我们终于能了解
It's an incredible evolutionary story that we can now unravel.
当提塔利克鱼的胚胎第一次成形，如同所有曾经活着的动物…
When Tiktaalik was first conceived,like every animal that ever lived,
它从一颗细胞开始，逐渐的形塑出身体，
it started as a single cell which slowly formed into a body.
小肢芽出现，
Small buds appeared
音猬因子这样的基因，将它们打造成鳍，
and genes like Sonic Hedgehog shaped them into fins.
经过数百万年后，
Over millions of years,
像这样的鳍…进化出了无数的形式，
fins like these evolved into a myriad of forms.
像是早期拥有八根指头的两栖动物，