生命的奇迹（2013）

And all four limbs are incredibly flexible.
各肢的末端都是手状结构
Each one ending in a hand whose curved bones
其曲骨适应于抓紧树枝
are perfectly adapted for gripping branches.
这些适应环境的特征被编码成指令
These adaptations are encoded in information
通过DNA传递
passed down in their DNA.
它戴了顶帽子
He's got a hat on.
它真的把帽子戴上了
He has actually just put a hat on.
这是红毛猩猩的基因序列
This is the orang-utan's genetic code.
它发表于2011年
It was published in 2011,
包含三十多亿个字母
and there are over three billion letters in it.
如果快速浏览一下...
If flip through it...
瞧瞧
Look at that.
它只由A C T G四个字母组成
Now, it's composed of only four letters, A, C, T and G,
这些被称为碱基
which are known as bases.
它们是化合物 是分子
They're chemical compounds. They're molecules.
运作的方式有种简洁美
And the way it works is beautifully simple.
它们三个一组 组成密♥码♥子
They're grouped into threes, called codons,
一些密♥码♥子会指令解码器
and some of them just tell the code reader,
这么说通俗点
if you like,
如何开始 在何处开始以及何时...
how to start, or where to start and when...
何时结束
and when it's going to stop.
它动作可真快
He's fast.
于是就有了起始点和终止点
So you'd have a start and a stop.
在这中间
In between,
三个为一组的密♥码♥子代表特定的氨基酸
each group of three codes for a particular amino acid.
氨基酸是组成蛋白质的基本单位
Now, amino acids are the building blocks of proteins,
蛋白质又是所有生物不可或缺的
which are the building blocks of all living things.
继续往下读
So you would just read along,
你会找到更多的起始点和终止点
you'd find, start, stop, and then
然后每三个形成一个氨基酸 形成氨基酸
you'd go along in threes, build amino acid, build amino acid,
形成氨基酸 形成氨基酸
build amino acid, build amino acid,
它们缩合就形成了蛋白质
stitch those together into a protein,
如果一直这样下去
and if you keep doing that,
最终你就会造出个红毛猩猩来
eventually you'll come out with one of those.
这当然没那么简单
It's not that simple of course.
但这就是基础
But the basics are there.
写在这里的遗传密♥码♥
This code, written in there,
就是造出它的指令
are the instructions to make him.
要想一代一代地
To faithfully reproduce those instructions
准确传递这些指令
for generation after generation,
红毛猩猩 以及地球上的万物
the orang-utans and, and indeed all life on Earth,
都依赖于DNA非凡的性质
rely on a remarkable property of DNA.
它具有惊人的稳定性及抗变性
Its incredible stability and resistance to change.
每一次细胞分♥裂♥ DNA需要被复♥制♥
Every time a cell divides, its DNA must be copied.
而基因序列在复♥制♥过程中耐错能力极高
And the genetic code is highly resistant to copying errors.
酶 负责进行复♥制♥的小型化学机器
The little enzymes, the chemical machines that do the copying,
在平均十亿个字母里只出现一个差错
on average make only one mistake in a billion letters.
这好比抄写280遍《圣经》
I mean, that's like copying out the Bible about 280 times
只抄错一个字母
and making just one mistake.
这样的精确度会让适应环境的特征如实地
That fidelity means adaptations are faithfully transmitted
由父母传向子女
from parent to offspring.
虽然我们认为
And so while we think of evolution
进化是个不断变化的过程
as a process of constant change,
绝大部分的遗传密♥码♥其实被保留了下来
in fact the vast majority of the code is preserved.
虽然我们与红毛猩猩的共同祖先
So even though we're separated from the orang-utans
要追溯回到一千四百万年前
by nearly 14 million years of evolution,
但令人惊奇的是我们和红毛猩猩的相似度
what's really striking is just how similar we are.
而且不只是表面上的相似
And those similarities are far more than skin deep.
红毛猩猩是最有人性的动物之一
Orang-utans are surely one of the most human of animals.
它们很多的行为特征
And they share many behavioural traits
被认为是人类独有的
that you would define as being uniquely human.
它们养育自己的孩子长达八年
They nurture their young for eight years
然后才让它们独自去森林里闯荡
before they let them go on their own into the forest.
这八年里小猩猩要学会分辨哪些果子能吃
In that time the infants learn which fruits are safe to eat
哪些有毒
and which are poisonous.
哪些树枝能承受它们的重量 哪些不能
Which branches will hold their weight and which won't.
之所以能学会 是因为它们有记忆
And they can do all that because they have a memory,
能记住生活中发生的事
they can remember things that happened to them in their life,
并从中学习
they can learn from them,
再代代相传
and they can pass them on from generation to generation.
我们不仅仅是和近亲
And that deep connection
拥有这种深刻的联♥系♥
extends far beyond our closest relatives.
因为我们的DNA里
Because our DNA contains the fingerprint
有近四十亿年进化的印记
of almost four billion years of evolution.
若绘制灵长类动物的生命树
If I draw a tree of life for the primates,
我们和黑猩猩还有
then we share a common ancestor
倭黑猩猩的共同祖先
with the chimps, bonobos.
生存于四到六百万年前
About four to six million years ago.
如果比较我们的基因序列
And if you compare our genetic sequences
你会发现我们的基因有99%是相同的
you find that our genes are 99% the same.
回到大概六到八百万年前
You go back to the split with gorillas,
和大猩猩拥有共同祖先时
about six to eight million years ago,
再一次比较基因序列的话
and again, if you compare our genes
会发现有98.4%是相同的
you find that they are 98.4% the same.
再往回看
Back in time again,
和那边的朋友 红毛猩猩拥有共同祖先时
common ancestor with our friends over there, the orang-utans,
我们的基因有97.4%是相同的
then our genes are 97.4% the same.
再一直往回看
And you could carry on all the way back in time.
你能找到我们与鸡的共同祖先
You could look for our common ancestor with a chicken,
我们的遗传密♥码♥大概有60%是相同的
and you'd find that our codes are about 60% the same.
实际上 任何一种动物 比如它
And in fact, if you look for any animal, like him,
一只小苍蝇 或是细菌
a little fly, or a bacteria,
表面上看起来跟我们完全没关系的东西
something that seems superficially completely unrelated to us,
但你仍会在其遗传密♥码♥中找到
then you'll still find sequences in the genetic code
与我的细胞中相同的序列
which are identical to sequences in my cells.
这告诉我们
So this tells us
地球上的生命都是相关联的
that all life on Earth is related,
遗传密♥码♥将生物联♥系♥起来
it's all connected through our genetic code.
DNA是生命的蓝图
DNA is the blueprint for life.
它的精确性 讲述着一个故事
But its extraordinary fidelity means it also contains a story.
多么奇妙的故事啊
And what a story it is.
生命进化的历史 从今日
The entire history of evolution from the present day
一直追溯到最初的生命
all the way back to the very first spark of life.
它证明了 我们不仅
And it tells us that we're connected,
与今日的动植物相关联
not only to every plant and animal alive today,
还与每一个存活过的生物相关联
but to every single thing that has ever lived.
前面的问题 什么是生命
The question, what is life,
一定是最深奥的问题之一了
is surely one of the grandest of questions.
我们也了解到生命并不是一个物体
And we've learnt that life isn't really a thing at all.
而是一系列的化学反应
It's a collection of chemical processes
利用能量的流动
that can harness a flow of energy
创造出秩序井然的个体
to create local islands of order,
比如我 还有这片森林
like me and this forest,
生命向广袤的宇宙借取秩序
by borrowing order from the wider universe
通过DNA发生的精巧化学变化
and then transmitting it from generation to generation
代代相传
through the elegant chemistry of DNA.
这一化学变化的开端
And the origins of that chemistry
可以追溯到四十亿年前
can be traced back four billion years,
最有可能源于原始海洋中的喷口
most likely to vents in the primordial ocean.
最神奇的是 这个在地球上
And, most wonderfully of all, the echoes of that history,
每个生物细胞中都能见证的历史印记
stretching back for a third of the age of the universe,
可以追溯回到宇宙寿命的三分之一
can be seen in every cell of every living thing on Earth.
这让我想到最振奋人心的一点
And that leads to what I think is the most exciting idea of all,
生命的出现 并非
because far from being
神秘力量导致的偶然事件
some chance event ignited by a mystical spark,
地球之所以出现生命
the emergence of life on Earth
也许是遵循物理定律所产生的必然结果
might have been an inevitable consequence of the laws of physics.
如果真是这样
And if that's true,
那么我们的宇宙必然生机勃勃
then a living cosmos might be the only way our cosmos can be.
请记住
Just remember
你是这星球上茫茫众生的一员