宇宙（2007）

The Universe S01E06

Part 4 April 22, 2021, 8:11 p.m.

如我们所知,像这些生物
the "oldest" organisms, the ones thatare nearest to the last common ancestor,
非常相似于远古的那些生物
are all thermophilic organisms.
都是这样的嗜温生物
And you could say, well that provesthat life evolved at high temperature.
你可能要问,生命如何在如此的高温下进化?
Descendents of these hot-bloodedorganisms can be found today
如今这些生物的后代,能适应更高的温度
and they can live attemperatures of 230篎.
能够生存在华氏230度的高温中
If you want some so called thermophiles,then you go to Yellowstone
如果你想见识这些所谓嗜温生物,来黄石国家公园
and you see these bubbling lakesand cauldrons of smelly water.
你会发现这些沸腾的湖,像煮沸的开水锅
And for years people assumedthey were sterile,
亿万年来,这里看起来依然是不毛之地
but they're full of life.
其实却充满着生命
And only these organisms*adapting to that extreme.
所有适合生存于此的生命体
Modern day extremophilesmay prove
这些现代嗜温生物表明
that life could have survivedand adapted
生命的能够生存和适应
under the extreme conditionson Earth during its turbulent infancy.
如地球早期的那些极端环境之下
But, how could single-celled microbestransform into complex life?
只是,这些单细胞生物
如何进化成复杂高等生物
Approximately 3 billion years ago,
大约在30亿年前
primitive lifesoaked up energy from the Sun.
原始生物靠吸收太阳能生存
Underwater microbes formeda green pigment called chlorophyll.
这些水中微生物具有叶绿素
This enabled themto trap sunlight
能够吸收太阳光
and produce a chemical reaction
并通过一些化学反应
which converts carbon dioxideand water into food.
把二氧化碳和水变成养料
This process, called photosynthesis,led the way for bacteria to multiply
这个过程,光合作用过程
使得这些细菌聚集起来
into one of Earth's earlier structures:cyanobacteria,
形成地球上的最初的多细胞结构,藻青菌
formerly called"blue-green algae".
就是所知的"蓝藻"
Cyanobacteria injected vast amountsof free oxygen into the water and air
蓝藻开始从水中大量释放氧气
爆发了一场氧气革命
and sparked the oxygen revolution.
All of a sudden, life dividedinto two groups.
不久,生命开始分两个方向进化
One that ran away from the oxygen andhid in the anaerobic part of the world,
一部分是无需氧气的厌氧生物
and the other thatstarted using the oxygen
其他的则使用氧气
as a great energetic advantage,
用来燃烧消耗能量
and then could evolve,I think, to be much bigger,
然后它们能够进化的更大
and perhaps to evolvemuch faster.
以及进化的更快
One thing is for sure, when thecyanobacteria got this ability,
相信这些蓝藻需要更大的身体
they outcompetedeverybody else.
与其他个体竞争
Thanks to cyanobacteria,life was able to quickly diversify
得益于这些菌类,生命快速地多样化起来
and become more complex.
变得越来越复杂
Without it, molecular oxygenwouldn't exist.
没有他们就没有氧分子的大量存在
Therefore, plants, animals and humanswould have never developed.
也将不会进化出任何动植物和人类
So if we didn't have the cyanobacteriawe wouldn't be around.
没有它们,怎能有今天的我们?
We owe our heritageto the scum of the Earth.
我们是这些地球微生物的后代
All of us came from the same place.
都从同一个地方进化而来
We have so many thingsin common with bacteria
我们都有许多共同点
跟这些微生物一样
that there's just no doubt about it.
这些是毋庸置疑的
The Mojave Desert,near Death Valley
莫哈韦沙漠死亡之地
in Southern California,appears void of life.
位于南加利福尼亚看起来没有生命
But below the surface ofthis dry lake bed,
但在这些干涸的湖床之下
mankind's ancestors thrive.
人类的最初远祖繁衍着
Planet Earth's earliest life forms
地球上那些最初的生命
may have adapted and perseveredunder extreme conditions.
能够适应如此极端的环境
Today, in the parched and barrenMojave Desert, in Southern California,
如今,在干旱荒芜的南加州莫哈韦沙漠
geobiologist Ken Nealsonis searching for the secrets to life.
地理生物学家 Ken Nealson整探寻着生命的秘密
He's discovered thatmodern microbial organisms
发现现代微生物们
also thrive in someinhospitable places.
依然繁衍在这样的不毛之地
What you see when you glanceat this environment are
观察这里,你能发现什么?
a bunch of what appear to betunnels or mounds here,
看起来是很多这样的沟壑与土堆
and these are made by the gasesproduced by the microbes living
却是由生活着的微生物排出的大量气体所造成
in this mudflat area.
而这原本是平整的土地
If we were to take water andrehydrate this piece of dirt
如果你带了水,并淋湿这块土壤
and put this under the microscope,
把它放到显微镜之下
it would be rife with abundantmicrobes swimming everywhere.
会发现水里飘满了微生物
And this is the lifecycleon the saltflat,
就是繁衍在这些贫瘠土地之中的生命
all of which we callextremophiles,
我们所称的这些嗜极生物
and which eke out an existencein a mudflat like this.
很好的生存于这样的荒原上
Microbes reigned supreme formuch of Earth's history.
微生物统治着整个地球
They revolutionized the planet
改变着整个世界
and paved the way for a myriadof sophisticated species.
为高等物种的出现创造了条件
But it was landthat gave life a new home.
不过,直到陆地的大块出现才给了生物们一个新家
It's believed the emergence of landmassbegan roughly 4 billion years ago.
也就是陆地上升时期
大约始于40亿年前
Plate tectonics createdheat and pressure,
地壳板块运动的不断加热和挤压
that produced rock lighterthan the ocean floor.
从海平面上升起大量岩石,陆地
It ultimately floatedand accumulated
随后,不断的飘浮与结合
creating continents that would changein size and shape over time.
形成了大块的陆地,并不断地改变的形状
The presence of vast continentswould enable Earth
地球大♥陆♥的出现
to sustain its mostdistinctive component,
承载着这独特的一切
complex life.
复杂高等生物
After 2 billion years of planetaryand biological evolution,
经过超过20亿年的不断进化
the first plants and animalsemerged from water onto land.
最初的两栖射生物开始爬上陆地
But it would take hundredsof millions of years
但是,数亿年后
before humans evolved.
人类出现
And once Man claimed dominanceover the planet,
自从人类统治这里
Earth would never be the same.
地球永远将是独一无二的
Planet Earth now holdsthe best real estate
地球是人类最佳栖息处
for mankindin our solar system.
在太阳系中
Seven diverse continentsand countless islands
7大洲和无数岛屿
are home to 6 billion people.
是60亿人口的家园
Yet, remarkably, most ofEarth's existence thus far,
非常难以置信地
生存于地球上多数时期的
has been without humans.
并不是人类
The planet's history has been comparedto a 24-hour clock,
将整个地球历史比作一个24小时的钟
with the presence of Man beingthe last 2 seconds of the day.
人类的出现只是1天的最后2秒钟
We're driving around the track nowat a relatively modest speed
我们现在围绕跑到缓慢驾驶
in this car that handles very smoothly.A very controlled ride.
这样,行驶平稳易于掌控
This reminds meof life on Earth.
对我来说就像地球上的生命
Life on Earth has hadits ups and downs,
盛衰变换着
but compared to evolutionof other planets
相比较于其他行星的发展
the Earth has had a relativelysmooth ride for billions of years.
数亿年时间里都非常相似
That's why life hasflourished here.
这就是生命繁衍于此的原因
But with mankind nownavigating its future,
现在,随着人类对未来的改变
Spaceship Earth may returnto its tumultuous beginnings.
地球这艘太空船开始发生剧烈变化
Humans, throughtrial-and-error evolution,
人类,使用各种改变
are suited to liveon this particular planet.
使得地球适合人类居住成为一个特别的星球
Now, that's true right now. We don'tknow if that will be true in the future.
就像现在这样,而不管将来如何
Earthlings created what once wouldseem almost unimaginable.
同样地,人类创造了大量难以置信的东西
Technology.
科技
Mechanical vehicles,gadgets and gizmos
车辆,机械和电子仪器
have simplified and betteredour lives.
简化并改进着我们的生活
Many of these conveniences are run onor made using fossil fuels,
多数设备或制♥造♥于化学原料或需要消耗化学燃料
which are harvestedfrom the Earth's crust.
都是从地壳中获得
But over the last hundred years,
但是,最近100年来
our innovations have gotten usinto planetary trouble.
我们的改变引起了一些全球化的问题
Humans are having a major effecton Planet Earth,
人类对地球的影响越来越大
with global warming,and population explosion,
像全球变暖和人口♥爆♥♥炸♥问题
so we're having a very large effecton the environment.
给环境造成巨大影响
The natural greenhouse effect
温室效应
is the absorptionof infrared radiation
是指大气吸收红外辐射
by our atmosphere,which warms our planet.
保持地球温暖
Without greenhouse gases, the Earth'ssurface would be up to 86篎 cooler.
没有温室气体
地球表面会比现在低86华氏度
But in the last 20 years there's beenan increase in greenhouse gases,
但是,最近20年温室气体增长过快
especially carbon dioxide
特别是二氧化碳
produced by burning fossil fuels.
产生于化学燃料燃烧
The increased heatingis affecting agriculture,
温度的上升直接影响到农业
sea level and weather.
海平面和气候
In the past, carbon dioxide levelshad spiked
过去二氧化碳含量也曾提升
due to natural causes,such as volcanic outgassing.
是自然火山生成的
However, today's rises seemto be happening much more rapidly.
然而,增长比想象的要快
To visibly witness thedrastic changes
为了观察,带来的最大的变化
one needs to travel to thebarely habitable zones on Planet Earth.
我们来到不适宜人类居住的地方
There, mankind抯 future
这个长的像人类的冰山将
is literally melting away.