生命的奇迹（2013）

这个小生命
This creature...
是大自然的奇迹
is a wonder of nature.
它生来便注定要在天空中飞翔
Its biology is hard-wired to the heavens.
它敏锐的眼睛追随着太阳
It has an exquisitely sensitive eye that locks onto the sun
以便在飞越大地的旅途中寻找方向
and allows it to navigate its way across the face of the planet.
从某种意义上说 它天生就知道
In a sense, it has an instinctive understanding
自己在太阳系中的位置
of its place in the solar system.
一只小昆虫的大脑
A tiny insect brain
与太阳和行星的运动联♥系♥在了一起
joined to the movements of the sun and the planets.
这种联♥系♥指引着这只帝王蝶和数百万只同伴
This connection steers the monarch and millions of its brethren
进行蝴蝶家族中距离最长的迁徙
as they make one of the longest migrations of any butterfly species.
这种树在当地被称为欧亚梅尔杉 或者神杉
They're heading for these trees, known locally as the oyamel,
它们正是为此而来
or sacred firs.
一些蝴蝶在四千公里外开始它们的旅程
Some of the butterflies began their journey over 4,000 kilometres away,
即两千五百英里
that's 2,500 miles,
从这里的美国东北部和加拿大
up here in the north-eastern United States and Canada.
经过秋天和冬天
And over the autumn and the winter,
它们向南迁徙 穿过美国
they've migrated south across the United States
到达这里 墨西哥中部
and arrived here, in central Mexico.
不可思议的是 没有蝴蝶学过这条线路
Incredibly, no butterfly has ever learned this route.
它们没有机会 因为至少需要历经三代
It can't have, because it takes at least three generations
才能完成整个旅程
to make the round trip.
作为替代 归巢的本能
Instead, the homing instinct is carried
被携带在遗传信息中代代相传
on a river of genetic information that flows through each butterfly.
这个地方对蝴蝶的吸引力
The allure of this place to the butterflies,
这种归属感 是我们共有的一片深情
this sense of belonging, is a deep feeling we all share.
我们甚至有一个词来形容它 家园
We even have a word for it - home.
所有我们已知的生物
Every living thing that we know to exist
都生存在这块巨石之上
is found on this one rock.
那么 是什么让我们的星球
So, what is it about our planet
成为如此富饶 多彩 生动的世界呢
that makes it such a rich, colourful, living world?
我要告诉你为什么我们的世界
I want to show you why our world
是宇宙中唯一已知 适合生存的行星
is the only habitable planet we know of anywhere in the universe.
几种珍贵的要素构成了我们的家园
Now, the answer depends on the presence of a handful
答案就藏在其中
of precious ingredients that make our world a home.
起初 上帝创造天地[出自《创世纪》]
In the beginning, God created the heaven and the earth.
地是空虚混沌
And the earth was without form and void.
渊面黑暗
And darkness was upon the face of the deep.
家园是一个能唤起记忆的词
Home is such an evocative word.
它对你来说一定有某种意义
I mean, it will mean something to you.
你上学的地方 你居住的地方
The place you went to school, the place you live,
你的孩子们度过第一个圣诞节的地方
the place where your kids had their first Christmas.
但从科学的角度来讲 家园意味着什么呢
But in a scientific sense, what does it mean?
它意味着 你赖以生存的种种要素
It means...that the ingredients are there for you to live.
空气 食物 水
An atmosphere, food, water.
你需要适宜的温度
You need the temperature to be right.
对于你的生物学功能和体内的化学反应
Home is the place that has the things you need
家园为你准备好了必需的要素
for your biology and chemistry to work.
这些同样也能唤起你的回忆
And it's no less evocative for that.
这里是墨西哥
This is Mexico.
它拥有的种种元素 铸就了我们的世界
A country rich in the ingredients that set our world apart.
这是个好地方
It's not a bad place to come
因为这里用地球表面百分之一的土地
because, with about 1% of the land surface area of our planet,
养育了百分之十二的物种
it's home to 12% of the species.
这里有两万六千种植物
There are 26,000 plant species here,
七百种爬行动物
there are 700 species of reptiles
和四百种哺乳动物
and 400 species of mammals.
这里也是一些伟大古文明的发源地
It's also been home to some of the world's great civilisations.
数千年前玛雅人就将他们的庙宇
The Maya built their temples out there in the forest here
建在那边的森林里
for thousands and thousands of years.
墨西哥是个生机勃勃的地方
Mexico is bursting with life.
如果你懂得观察 这些生物身上藏着的线索
And if you know where to look, hidden inside these creatures
解释了为何地球能够成为我们的家园
are clues that tell how this planet became their home.
第一站在这个国家的东南部
First stop is in the southeast of the country.
一个被密林覆盖的地方
An area covered in thick jungle.
尤卡坦半岛由纯石灰岩构成
The Yucatan's a strip of essentially pure limestone
将加勒比海与墨西哥湾隔开
that separates the Caribbean from the Gulf of Mexico.
如果要构成一个丰富多样的生态系统
And it's got all the ingredients you might think you need
所需材料在这里应有尽有
for a rich and diverse ecosystem.
热带的阳光温暖着森林
The tropical sun warms the forest,
向每一片树叶输送能量
delivering precious energy to each and every leaf.
植物和树木释放出氧气
Oxygen escapes from the plants and trees,
使林中的动物得以呼吸
which is breathed in by the forest animals.
无时无刻 所有动物
And where they can, each of them
都在贪婪地汲取着这片区域的隐藏水源
draws deeply from the region's hidden water supply.
但为了养育这样的热带雨林
But there are some of the ingredients you need
某些要素比其他成分
to grow this tropical forest
要重要许多
that are far more important than others.
你也许会觉得这地方到处都是水
You might think that this place would be awash with water.
这里确实雨水充沛而且异常潮湿
And it does rain a lot and it's incredibly humid.
实际上 尤卡坦半岛并没有任何地表河流
But actually, there are no surface rivers at all on the Yucatan Peninsula
因为水都渗入了多孔的石灰岩
because the water just seeps into the porous limestone.
那就是这些东西形成的原因 这是溶井
That's where these things come in. These are cenotes.
它们是雨水溶解石灰岩 构成的巨大洞穴
They're caverns dissolved out of the limestone by the rain.
它们能收集雨水
And they collect water.
并在生态系统中扮演重要角色
And they play a vital role in the ecosystem.
当你靠近溶井时雨林就变得不同
I mean, the forest changes when you get around a cenote.
听那个声音
Just listen to that.
那些是蛙鸣
And those are frogs.
在林中的其他任何地方你都听不到蛙声
And you don't hear those frogs anywhere else in the forest,
除了在溶井周围
just around the cenotes.
这些溶井是
The cenotes are flooded caves
与世隔绝数千年的水淹洞穴
that have been cut off from the outside world for thousands of years.
睡莲 穴居鱼类 甚至偶尔出现的龟
Lilies, troglodytic fish, even the occasional turtle,
都在这些淡水井口附近繁衍生息
all thrive around the openings of these freshwater wells.
当我深入洞穴时
As I head deeper into the cave,
温度开始下降 光线也变暗了
the temperature drops and the light fades.
我赖以生存的东西开始逐渐消失
One by one, the ingredients I depend upon begin to disappear.
即使是在这里 远离土壤和空气
Yet even here, far from the soil and air,
颜色怪异的藻类依然能在水中安家
strangely-coloured algae still find a home in the water.
如果有一样东西能将溶井中的每种生命形态
If there's one thing that unites every form of life in the cenote,
实际上是这片森林中的每种生命形态
in fact, every form of life out there in the forests,
实际上是我们在地球上已发现的
in fact, every form of life we've ever discovered
所有生命形态联♥系♥起来
anywhere on planet earth,
那就是水
it's that it has to be wet.
只有在地球上 水可以在天空
Only on our home does water run freely between the skies,
海洋和河流间
oceans, rivers
以及所有生物体内循环流动
and on, into every living thing.
为了理解为何生命和水紧密相连
To understand why life and water are so intertwined,
我们要深入观察一下
we need to look a little deeper
我们知道的 最奇怪的一种物质
into one of the strangest substances we know.
虽然现在我看起来可能像个中年学究
Now, I may be a bit of a middle-aged academic,
但我依然会时不时做个奇怪的实验
but I can still do the odd experiment every now and again.
我正在给这支有机玻璃棒充电
So what I'm doing is I'm charging up this Perspex rod.
把它在皮毛上摩擦可以使它带电
So giving it an electric charge by rubbing it on the fleece.
现在看看发生了什么
Now, watch what happens...
当我把玻璃棒靠近水流时
when I put the rod next to a stream of water.
看到了吗
You see that?
看看这个
Look at that.
电场和电荷
The electric field, the electric charge,
让水流向玻璃棒弯曲
is bending the water towards it.
这种情况发生的原因
Now, the reason for that,
当水流穿过电场时
the reason that water behaves in that way
发生弯曲的原因
when it's passing through an electric field,
正是水对地球上所有生命都至关重要的原因
is exactly the same reason that it is vital for all life on earth.
水是一种极性分子
Water is a polar molecule,
这意味着电荷能对它起作用
which means it responds to electric charge.
它的极性
Its polarity comes about
来源于它的分子结构
because of the structure of water molecules themselves.
水是一氧化二氢
Now, water is H2O,