种出个地球（1）

观察这个简单的电化反应
And we should see a simple reaction.
不错不错 有气泡出来了
Oh yeah, yeah. There's some bubbles coming off.
这些泡泡就是氧气
These bubbles are the gas oxygen.
历经25亿年
It's being released for the first time
禁锢在这块矿石中
in over two and a half billion years,
终于首度现出真身
when it was locked away in the rock.
气泡连成一条曼妙的细线
There's a lovely little train of them
欢腾地上升 排出一个小气室
just rising to the top and forming a little pocket of gas.
没人知道这样的试验
You're never sure with these experiments
是不是能够成功
whether you're really going to get it or not,
不过 我要的效果的确出现了
but that's exactly what I was hoping to see.
不过一个小时 我就制取到了
In just one hour, I've collected enough
满满一试管的氧气
to fill the whole test tube.
关键是 这可不是随便什么氧气
The thing is, this isn't any old oxygen.
这是铁矿层里制取的氧气
This is oxygen that's come from those iron bands.
是改造过这颗星球的氧气
The very oxygen that changed our planet.
我真忍♥不住了 我必须...
In fact, I can't resist it. I'm going to have to...
真难以置信
I can't believe it.
我吸的是
I'm breathing oxygen that was made
25亿年前产生的氧气
two and a half billion years ago.
没有了 从矿石中解脱
It's all gone. Liberated from the rocks now.
又消散在空中
It's up there somewhere.
这些铁矿层讲述了一个非凡故事
These iron bands tell a remarkable story.
在那时候氧就充斥着地球大气
Oxygen was now flooding the Earth's atmosphere.
遥想当时 它去除了大气中的有毒气体
It cleaned out the planet's toxic gases,
第一次让天空变得湛蓝清澈
leaving the sky a clear blue for the first time.
地质学家称之为"大氧化事件"
Geologists call it the Great Oxidation Event.
这绝对是个大事件
And it certainly was an event.
这是在截然不同的两个世界
This was an irreversible change
上演的一场不可逆变革
between two very different worlds -
一个是没有游离氧的早期地球
a planet with virtually no free oxygen
一个是今天富氧的地球
and a planet full of oxygen.
这是地球生命史上浓墨重彩的一笔
This was the greatest change in the history of life on Earth.
那么 这个大事件是如何发生的呢
So how did this great event happen?
答案就在于首次生命大爆发
The answer lies with the first burst of life,
严苛的陆地难堪此任 这发生在水下
which emerged not on the hostile land but under water.
当时
Back then,
水担负起过滤致命紫外线的重任
water acted as a liquid sunscreen to the dangerous UV rays.
在水体保护下
Under the protection of water,
地球上早期的有机体
the earliest organisms on Earth evolved
以细菌形态逐渐演化
in the form of tiny bacteria.
这里是东非 我们将得以一睹
And here in East Africa is a rare chance
那由细菌形成的世界
to see what it would have been like.
这里是马加迪湖
This is Lake Magadi.
湖水含盐量很高
The waters here are just super salty.
一踏上去 就能感觉到水都是滑溜溜的
Can feel it nipping away at my feet.
我趟过的这片湖水中的细菌
But the bacteria I'm wading through are close descendants
是早在三十亿年前在地球上出现的
of the very first microorganisms
微生物鼻祖的直系后代
that lived three billion years ago.
想想就很奇妙
It's fantastic to think
在这水面上浮游的生物
that swimming in the top layer here
竟属于地球上最古老的生命形态之一
are some of the most primitive life forms on Earth.
三十亿年过去了
And those bacteria,
这些细菌还是当初的模样
just like the ones all that time ago,
并为我们带来了一些惊喜:
have got something surprising about them.
它们竟是紫色的
They're purple.
我们应该膜拜这些细菌
These are hallow bacteria
它们并非只是随性地在这个湖中安家落户
and they didn't just occupy the occasional lake.
三十亿年前 世界上所有的海洋
Much of the world's oceans
也都是紫色的
were purple, too.
试想一下 从外太空望去
Imagine that from outer space.
那是一个紫色的地球
A purple Earth.
这种紫色的细菌
The purple bacteria live by
依靠吸收太阳的能量而生长
harnessing energy from the sun.
但在太阳光中 只有一部分能为其所用
But they only use part of the light.
只有一部分光线能够穿透到水体的更深层
Some rays pass deeper into the water.
在水体深处 通过经年累月的进化
And over time, down there,
细菌中的新物种出现了
a different type of bacteria evolved.
它们只能依靠水体深处残存的光线生存
They had to live off the colours of light left over.
而这使得它们呈绿色
This made them appear green.
这就是绿细菌
These were the green bacteria.
这看上去显得非常偶然的演化过程
This seemingly arbitrary event,
即细菌碰巧吸收了这种颜色的光线
bacteria absorbing one colour of light
而非其他颜色的光线
rather than another,
却间接地对地球产生了极为重大的影响
would have colossal repercussions for the planet.
久而久之 这些绿细菌
Over time these green bacteria,
亦即蓝绿藻中的一种
a type of Cyanobacteria,
逐渐主宰了这个世界上所有的江河湖海
came to dominate the waters of the world.
最终 正如我们所见
Eventually, as we'll see,
地球上所有的植物
these green microorganisms
都是由这些绿色的微生物进化而来的
became the ancestor of all plants on Earth.
由于从一开始
Because right from the start
这些植物的先祖们就只反射绿色光线
they were reflecting green light,
因而植物的茎叶
the stalks of the plants
也随之而呈现出绿色
became green and the leaves were green.
也正是因此地球上所有植物都呈绿色
In fact, that's why all plants on Earth became green,
从草丛到森林 无一例外
from the grasses to the forests,
这也为我们解释了
and it's also why today,
为何今日的地球并非是紫色的
instead of living on a purple planet,
而是一颗绿色地球
we've got a green one.
然而这并不仅仅只是颜色的问题
But it wasn't just about colour.
因为绿细菌拥有一些
Because the green bacteria did something
紫色细菌并不具备的能力
their purple cousins couldn't.
那就是 制♥造♥氧气
They produced oxygen.
它们为这不毛之地带来生命的气息
They would breathe life into the lifeless land.
若非它们 我们的地球
Without them, the story of our planet
就会像火星一般荒芜
would be more like that of Mars.
绿细菌是如何制♥造♥氧气的问题非常复杂
How the green bacteria did this is so complex
科学家们仍在努力梳理其中的细节
that scientists still grapple with the details.
我在康沃尔郡的伊甸园工程研究所
I've come to the Eden Project in Cornwall
试图解开这个谜团
to try to understand it.
这是一项从未有人尝试过的试验
I'm to be the subject of an experiment
而我将作为这个试验的试验对象
that's never been attempted before.
我就是你们试验用的小白鼠了
I'm the guinea pig.
我猜 你是个博士吧
Doctor, I presume?
是的 我是丹·马丁
Indeed. Dan Martin.
幸会 -你好 我是卡特里娜·霍普
Hi there. - Hi. Katrina Hope.
很高兴认识你
Nice to meet you.
看看啊 这简直太酷了
Look at this! This is fantastic.
简直是难以置信 不是吗
Incredible, isn't it?
一会儿我将被锁在这个完全密封的房♥间中
I'm about to be locked inside this airtight chamber.
我很期待亲身经历一场
I hope to experience first-hand
氧气制♥造♥的非凡过程
my very own Great Oxidation Event.
好了 大家各就各位
OK, everyone.
现在我要开始降低
I'm going to start reducing
丹尼尔·马丁 博士
房♥间中的氧浓度了
the oxygen concentration in here now.
第一个步骤就是将房♥间中的含氧量
The first step is to lower oxygen levels
降低到地球诞生初期的水平
closer to those of the early Earth.
请先戴上这个
So first of all,
卡特里娜·霍普 博士
它将监控你的心率
this is going to monitor your heart rates
以及你体内的含氧量
and your oxygen levels,
等我们把监控仪打开
so if we pop that on
就能看到你身体的各种参数了
we can just have a look here.
高等生物 比如我们人类
It's a lack of oxygen that
无法长久在缺氧的环境中工作与生活
complex life like us can't operate at for long.
上面那个图像显示的是你的心率
So at the top is your heart rate.
我的心率怎么样 是不是太快了
How's that? Is that really high?
我觉得你是一想到要进入那个房♥间
I think you might be a little bit anxious
就有一些焦虑
about going in there.