动物的末日（2009）

现在托巴的火山口终于平静下来了
Toba's caldera finally falls silent.
但是这并不能给地球上的动物带来任何的安慰
But any comfort this is to the animals of earth is quickly crushed.
托巴火山喷发已经引起了灾难性的连锁反应
Toba has set in motion a catastrophic chain reaction.
正所谓这场灾难始于酷热 终于寒冷
What began in fire will end in ice.
"延缓死亡比死亡本身更加痛苦"
"Death is less bitter punishment than death's delay."
奥维德在公元前1世纪时这么说道
Ovid, 1st Century B.C.
托巴超级火山终于安静了下来
The Toba supervolcano has fallen silent,
但它爆发时所释放出来的污染物
but the pollutants released in the eruption
带来了新一波可怕的灾难
usher in a nightmarish new phase of the disaster.
那就是造成了全球气候的致命变化
Global climate change.
过去180万年来
For the past 1.8 million years,
气候就像个跷跷板一样在冰河时期和相对温暖的时代间来回起落
the planet has seesaw between ice ages and times of relative warm,
这个温暖的时期叫做间冰期
called interglacial periods.
当托巴火山喷发时 地球正处于间冰期
When Toba erupted, Earth was interglacial.
有些科学家认为
Some scientists theorize
这次超级火山爆发使得下一个冰河时期提前开始
the supervolcano triggered the next Ice Age.
火山爆发重要的一点是会与环境发生交互作用
That's one of the big things about these volcanic eruptions is they produce feedbacks,
也就是说温度会逐渐下降
That is they start cooling,
如果威力足够的话
and then if it's enough,
气候系统的其它部分就会与其发生反应
then other parts of our climate system react to a respond
作为回应 或许温度就会下降得更厉害
and maybe enhance the cooling.
火山能够改变气候的关键
The key to the volcano's climate changing force
是在于它喷发所释放的气体中的硫含量
is the sulfur content in the gas it releases.
二氧化硫是最能影响到气候的气体之一
One of the most significant gases that can influence climate is sulfur dioxide,
如果含硫的气体能够上升到平流层
sulfurous gases if they can get into the stratosphere,
就可以在上面停留很长的时间
can reside there for long periods of time.
然后我所说的很长时间指的是好几年
And when I say long periods of time, I mean several years.
当二氧化硫到达平流层之后
When sulfur dioxide we choose the stratosphere,
就会转变成硫酸盐粒子
it transforms into sulfate particles,
把太阳的能量反射回太空
that radiates the Sun's energy back into space.
地球在失去了孕育生命的阳光之后
Cut off from life-giving Sun light,
就会开始急速冷却
the Earth below begins a massive cool down.
这种回力棒效应会带来很严重的后果
A boomerang effect with epic consequences.
在1815年坦博拉火山喷发之后
When Mount Tambora eruption in 1815,
就迎来了没有夏季的一年
it's on the year without a summer,
导致当地的农作物歉收 发生了很严重的饥荒
crop failures and famines ensued.
科学家认为比坦博拉火山爆发威力大50倍的托巴火山爆发
Scientists theorize that Toba an eruption 50 times larger than Tambura,
或许会对全世界产生同样的效应
may have had a similar effect all over the world.
火山爆发造成全球陷入寒冬好几年
The eruption caused a global winter for several years,
导致植物变少 人类可猎杀的动物也开始减少
which would have resulted in much fewer plants fewer wildlife for people to hunt,
这当然会造成很严重的饥荒
and it would have essentially caused starvation.
五年过去了
5 years pass,
太阳光穿不透那烟雾云层 让地球变温暖
the sun can't break through the smoggy cloud layer to warm the Earth.
温度急剧下降了5到10℃
Temperatures plummet 10 to 30 degrees.
如今的我们听起来这好像并不算什么
Though it might not sound so drastic to us,
但是温度下降却对我们的古老祖先造成了致命的打击
the temperature dropped devastates our ancient ancestors.
他们从来没经历过10℃以下的气温
They've never had to deal with temperatures below 50 degrees.
74000年前 地球上的人类还不太多
74,000 years ago, there were not very many of us on this planet,
这是一个很严重的问题
and that's the big problem.
74000年前发生了超级火山喷发这样的大灾难
74,000 years ago we get this huge disaster of this volcanic extravaganza,
而当时的人类数量又不多
at a time when human populations are so small,
这样人类很容易会彻底走向灭绝
that there could have been the total extinction of humanity quite easily.
人类的数量正在急剧减少
The human population dwindles,
有几十万人死于非命
hundreds of thousands died,
这是人类历史上最为黑暗的一章
it is the darkest chapter in the history of the human race.
通过研究我们人类的DNA
Based on study of our own DNA,
科学家发现当时人类的数量可能只剩下两万人
scientists theorize the human population may have bottlenecked to his few as 20,000 individuals.
我们可以通过研究现代人们身上的DNA序列的多样性
What you can do is look at the diversity of DNA sequences that are present in modern humans,
来计算出从很久以前到现在为止基因组到底经过多少次变化
calculate how much how much variation there has been back through time.
这样你就会发现
And you can see that
跟其它的物种比起来人类的变化要相对少得多
humans actually have relatively low variation relative to a lot of species,
出现这种情况的原因是不久之前人类曾经遇到过发展瓶颈
and the reason for this is because it was very recently that we actually had this bottleneck.
人类基因组的总体变化受到了很大的限制
The mass variability of the human genome constricted right down.
因此这就叫做瓶颈期
That's why it's called a bottleneck.
瓶子下面很宽 然后中间有个很狭窄的瓶颈
The bottles a big open thing and then you got that tint little neck,
你从瓶子里倒东西出来时一定会经过那里
you have to get through that if you're pouring out.
当经历了那次事件之后就没有太多东西能够通过瓶颈了
Well, there's much to get through after this particular event.
温度在持续下降
Temperatures continue to drop,
冰冷的气候成了常态
icy conditions become the norm.
人类正濒临灭绝
The human race teeters on the edge of extinction.
距离托巴火山爆发已经过去了十年
10 years after the Toba eruption,
火山灰等其他污染物终于从大气里冲走了
the action pollutants finally wash out of the atmosphere.
地球非常努力地从灾难中恢复过来
Earth tries to recover from the disaster,
但这一路下来可是相当的艰辛
but the path is arduous.
当地球正在经历火山严冬之际
Pushed over the edge by the volcanic winter,
南北两极的冰雪开始堆积起来
snow and ice begin collecting over the poles.
堆积几千年之后形成了庞大的冰川
Over the course of thousands of years massive glaciers form,
并开始慢慢地朝赤道地区移♥动♥
and slowly creep toward the equator.
对于已经饱受超级火山爆发所带来灾难的地球来说
For a planet already stunned by the supervolcano's wrath,
这次冰河时期的到来或许是来送终的
this Ice Age maybe the nail in the coffin.
现在是一万年前
It's 10,000 years ago,
托巴火山爆发至今已经超过了六万年
over 60,000 years since Toba erupted,
它的爆发差点就让人类绝种
the supervolcano nearly drove our species to extinction,
但是智慧和创新将他们从灭绝边缘中救了回来
but intelligence and innovation have brought them back from the brink.
随着冰河时代的结束 地球开始变得温暖起来
As the Ice Age ends and the world thaws,
人类成为了世界上最顶级的掠食者
man becomes the world's top predator.
几千年以来 猛犸象一直是他主要的食物来源
And for thousands of years, Mammuthus have been their chief food source.
有些科学家认为由于人类过度捕猎导致猛犸象绝种
Some scientists theorize that human hunting drove the Mammuthus to extinction.
每年只要消灭一个象群里除自然死亡以外2％的小象
We have to take out about 2% of the babies of an elephant population per year,
就可以让它们在500年内绝种
more than nature, otherwise would to cause an extinction about 500 years.
人类只要再多杀几只乳齿象和猛犸象
It would have only taken some humans taken out a few more mastodons Mammuthus,
数目超过它们的自然死亡率 就足以造成它们绝种
and would have otherwise we take into caused their extinction.
在这场激烈的生存之战中
In the epic fight for survival,
人类的创新本能和不断进步的技术让他们得到了优势
it is man's Innovative nature and ever advancing technology gives them the edge.
梭镖这种新武器
One new weapon the Atlatl,
只是一根一端挖了个凹槽的棍子
is a simple stick with a cup carved at one end,
使用它的人只要把矛放进凹槽里
by inserting a spear into the cup,
就能利用杠杆原理增加射程
the thrower can then use leverage to improve his range.
这样的武器让猎人们可以从更远的距离攻击
The Atlatl now gives human hunters the ability to attack from further away.
以前他们可以把矛射到60多米远的地方
They could throw their previous spears about 200 feet,
现在这种改进就让射程翻倍
this modification more than double that range.
古代人类的生活只要过得越艰苦
The tougher life became for ancient humans,
他们就越能想出新的生存方式
the more they pioneered new ways to survive.
他们拥有的智慧和工具能够确保我们的物种存活下来
Their intelligence and tools ensure the survival of our species.
所有问题之中最耐人寻味的是
One of the most fascinating of all questions is,
这次大灭绝是不是真的造就了我们？
whether this particular event actually improved us,
让人类更像我们现在的样子
improve in the sense that making this more as we are now.
进化看起来是跟生存有关 但事实上是跟死亡有关
Evolution seems to be about life, it's really about death.
死亡使进化有效进行着
Death makes evolution work,
然后进化会从死亡中学习
and death evolution is looking back.
你获得的一系列生存基因
It is the the series of genes you got from the survivor ability
就是继承了我们祖先能够在那场生存之战中存活下来的基因
of the group before you, adapted that time before you.
可惜的是在托巴火山爆发之后
Alas in the wake of Toba,
很多其它的大型哺乳类
many other species of large mammals,
巨猿
Gigantopithecus,
洞狮
Panthera leo,
还有板齿犀 都永远地消失了
Elasmotherium, disappear forever.
但是以大灭绝的巨大规模来说
But on the grand scale of mass extinction,
托巴火山爆发不过是个小光点
Toba is just a blip.
热带的雨水把托巴火山的庞大火山口变成了湖
The tropical rains turned the volcanoes massive caldera into a lake,
它至今还存在 几乎没有留下任何痕迹
that still exists today.
没有任何迹象表明这里发生了改变世界的可怕大灾难
Leading scarcely any sign of the terrible catastrophe that changed the world.
但是这一切还没有结束
But it's not over,
地壳下的熔岩还在继续翻腾
underneath the crust, magma still rages.
这意味着随时都有可能发生像托巴火山那样的超级火山爆发
super volcanic events like Toba can happen at any time,
随时威胁着我们的命运
leaving our species at risk.
事实上科学家们认为
In fact scientists believe
我们跟古老祖先比起来或许会更没有能力来应对这场危机
we may be less prepared than even our ancient ancestors to deal with the crisis.
75000年前 早期人类一定要什么都会
75,000 years ago these early hominids had to be jack-of-all-trades
才能够在那种环境里生存
in order to survive in that kind of a habitat.