动物的末日（2009）

它们是奥陶纪时期的杀戮机器
the killer whales of the Ordovician,
但是现在它们变得弱不禁风 彻底沦落为绝望的食腐动物
now weak and sickly, they are desperate scavengers.
对于它们来说 世界已经完全变了样
For them, the world is vastly different.
地球一年比一年寒冷
Year by year, the planet is getting colder and colder.
你现在看到的是新冰河时代的诞生
What you're witnessing is the birth of a new ice age.
冰雪在南极堆积起来
Snow piles up at the South Pole,
经过几个世纪之后 冰雪被压缩成固体的冰层
and over centuries, it compacts into solid sheets of ice.
1公里厚的庞大冰川慢慢往北流动
Immense, mile thick glaciers that slowly march north
越过位于南极上方的超级大洲 冈瓦纳古大♥陆♥
across Gondwana, a super-continent situated over the South Pole.
越来越多的冰川吸走大量海水
The growing glacier suck up vast amounts of ocean water,
让海平面下降了将近60米
causing sea levels to drop by up to 200 feet.
海洋里的海水减少 导致海平面下降
The water was taken from the oceans and sea level declined.
冰结得越多 海平面就越低
More ice, the lower the sea level.
到最后各大洋的浅海海道全部干涸
And eventually it drained the continents of their shallow sea ways.
栖息在那里的生物因为没有足够的生存空间而死亡
And the organisms living there had no living space, they died.
因浅海消失而死亡的地球生物
The loss of the shallows wipes out more of Earth's population
其数量远超过伽马射线大爆发时所造成的灭绝事件
than the gamma-ray bursts itself.
就某种意义上说正好跟我们今天所担心的事情相反 对吧
In a sense, it's the opposite of what we're worried about today, right?
我们目前在间冰期里担心冰川融化
So right now we're in a glacial period, and we're worried about the glaciers melting,
你看着北美洲的地图
and you see maps of North American,
或许会担心弗罗里达州会消失
but of well there goes Florida,
曼哈顿不见了 低洼地带全都不见了
there goes Manhattan, there goes, you know all the lowlands.
当时的情况正好相反
So basically this is the reverse,
海水被冻在广大的冰川之中 导致大洋有很多地方都暴露出来
quite a bit of continent gets exposed, when you tie up water into widespread and glaciers.
让人意外的是
Surprises,
在这个新冰河时代里 有些动物展现出了不起的适应能力
in this new Ice Age, some animals proved remarkably resilient.
我们的古老祖先星甲鱼
Our ancient ancestor, Astraspis,
追随着逐渐消退的海水
follows the receding ocean water.
这种早期脊椎动物比其它海洋生物更能忍♥受冰冷的海水
This early vertebrate indoors cold water better than other sea creatures.
不挑食的习性对它的存活有很大帮助
Even more critical to its survival is it's in discriminating palate,
它们几乎有什么就吃什么
which allows it to eat anything that's available.
星甲鱼不单单能适应艰苦的环境 甚至还能大量繁殖
Astraspis is adapting, even flourishing through the hardship,
不久之后 就进化出大量新品种的鱼类
and soon an entirely new variety of fish begins to evolve.
这些新的鱼类
In these new species,
组成了原始鱼鳃的骨骼和肌肉
the bones and muscles that form the first gill,
而且有了新的功能
take on a new function.
就是把食物分类 并把大块的食物推下喉咙
Sorting and moving large food particles down the throat.
脊椎动物的各种双颚
Every jaw in the vertebrate world,
不论是用来咀嚼反嚼的食物 还是咬住猎物
whether it's used for chewing cud, taking down prey,
还是只是说话这种简单动作
or the simple act of speaking,
都是来自这种了不起的适应能力
is the result of this remarkable adaptation.
另一种十分坚强的动物是板足鲎类
Another animal that's persevering is Eurypterid.
这种掠食动物也跟着消退的海水
This predator also followed the receding ocean water,
在取代了鹦鹉螺在食物链的地位之后 成功地存活下来
and managed to survive by taking over the Natiloid's niche in the food chain.
因为板足鲎类的身体只有鹦鹉螺的一半大
Since Eurypterids are half the size of the Natiloids,
它们所需的食物也少得多 这是它们生存下来的关键
they need far less food, a key to their survival.
在全世界的海岸线上
On coastlines across the world,
下降的海平面造成了很奇特的地形
the drop in sealevel creates bizarre landscapes.
珊瑚礁的残骸现在露出了海面
The skeletons of coral reefs are now jutting above the surface.
曾经直壳鹦鹉螺称霸过的地方
Where straight Nautiloids once ruled,
现在只有少数虚弱的幸存者在荒地上寻找着食物碎屑
now a handful of weary survivors search the wasteland for any scrap of food.
很多动植物的适应能力都很弱
So many animals and plants are narrowly adapted,
特别是对热带生物来说
and any sort of cooling,
遇上任何气温下降的情况都活不了
especially for tropical creatures is a death sentence.
拿个庞大的玻璃瓶罩在夏威夷上
Take an enormous glass jar and put it over the island of Hawaii,
让它冷却二个月之后再回来看看 还能有多少植物活下来
cooled off for 3 months, and come back and see how many of those plants are alive.
随着冰川不可阻挡地进入亚♥热♥带地区
As the glaciers forge their way into the subtropics,
巨大的冰山出现了
huge icebergs appear.
在地表之下 它们想试图摧毁它们前进道路上的一切
Beneath the surface, they threatened to destroy everything in their path.
就像冰山一样 它们滚滚地向赤道前进
As mountains of ice, steamroll their way toward the equator.
形成了几千年之久的珊瑚被彻底碾碎
Coral, thousands of years old, is plowed over,
造成了巨大的破坏
causing massive devastation.
距离大灭绝发生已经过去了25万年
A quarter of a million years into the extinction,
海平面还在继续下降
sea levels continue to drop.
几千平方公里的海洋栖息地
And thousands of square miles of marine habitat
都暴露在地表世界的恶劣环境里
are exposed to the harsh conditions of the surface world.
阳光和风雨侵蚀着珊瑚礁
Sun, wind and rain erode the reefs,
把它们变成辽阔荒凉的沙漠
transforming them into vast baron deserts.
年复一年 动物们一直跟着消退的海水后撤
Year by year, life retreats with the receding ocean,
海洋的栖息地正变得越来越小
condensed into ever smaller habitats.
这是强迫性的迁徙
So this is forced migration you know,
你也许能迁徙到更好的地方去 但也许不能
this is migration maybe doing a better place, but maybe not.
水温和洋流一定都改变了
Water temperatures, ocean currents, would have changed.
热带会变成温带 最后变成寒带
Conditions of a tropical world would have gone temperate and finally to frigid it,
发生的这一切就导致了大量物种的灭绝
so all of this would have contributed to extinction.
伽马射线大爆发至今已经过去55万年了
It is now 550,000 years after the gamma-ray burst,
酷寒的环境已经消灭了地球上将近三分之二的动物
freezing conditions have annihilated two third of the world's animals.
但是这时候气温开始回升 冰川开始融化
But then temperatures rebound, the glaciers melt.
在冰河时期存活下来的动物
Species that survive the ice age,
又要在另一次极端的环境变化中面临严峻的考验
struggle through yet another extreme environmental change.
跟之前一样 运气决定了谁能生存下来
As always, luck factors heavily into who will survive.
我们在看奥陶纪时期的集体大灭绝时
As we look at the Ordovician extinction,
有一点是很突出的
the one thing that really stands out,
生存下来的最好方式就是分布广泛
is that the best way to survive is to be very widely distributed.
如果一个物种分布在五到六个大洋
The same species is present on five or six different continents,
它们就很有机会存活
it has a very good likelihood of survival.
如果只栖息在一个大洋 很大概率会活不下去
If it's present only on one continent, it's very unlikely to survive.
让人惊奇的是直壳鹦鹉螺东山再起
Straight Nautiloids make a surprising comeback,
但是它们和之前大不相同
but they're a shadow of their former selfs.
它们的身长曾经超过6米 现在只有之前的一半左右
They used to grow to over 20 feet, now there have half that.
它们比祖先柔弱得多
They are far weaker than their ancestors,
而且得时刻面对被攻击的威胁
and under constant threat of attack.
跟曾经强势的鹦鹉螺不同
Unlike the once dominant Nautiloid,
板足鲎类在灭绝期间一直过得不错
Eurypterids have fared well through the extinction.
现在掠食者和猎物的角色
The roles of predator and prey,
倒反过来了
are now reversed.
海洋成了血腥的杀戮战场
The oceans become a bloody killing field,
但是这次板足鲎类成了霸主
but this time is Eurypterid's dominate.
在这个不断变化的世界里
In this changing world,
这些海蝎出现了一种奇特的新行为
these sea scorpions are exhibiting a curious new behavior.
它们捕猎完成之后就经常会把食物拖到岸边
Once they make a kill, they often drag the carcass toward shore.
不可思议的是 有些海蝎还会冒险上岸
And incredibly, some of them are even venturing onto land.
不断改变的海平面
It is possible that the shifting sea levels
或许让呼吸空气的书肺加速进化
may have accelerated the evolution of air breathing book lungs,
就像很多现代昆虫的肺部
like those in modern insects.
板足鲎类的腹部里
Inside Eurypterid's abdomen,
有很多层叠起来的空气包 就像摺起来的书本一样
are stacks of air pockets, resembling a folded book.
海蝎的血液在这个组织里循环
The scorpions blood circulates through this tissue,
呼吸着空气中的氧气
pulling oxygen out of the air.
这是靠求生意志促成的强大适应能力
An amazing adaptation born out of the will to survive.
集体大灭绝就像是在刚除了杂草的花♥园♥里施肥
The mass extinctions are like dumping fertilizer on on a newly weeded garden.
之后那里又会长出很多东西
You get a lot of stuff back,
有些是可以预料到的 但也有些是全新的
some you can expect and some is totally new.
如果没有发生那次集体大灭绝的话
Had that mass extinction not have happened,
我可以确定到了如今 地球上的动物和植物会大不一样
I can guarantee that the types of animals and plants we have on the planet today would be different.
在同样的水域里 出现了另一种了不起的进化
But in these same waters, there's another remarkable evolutionary trait emerging.
这一小群鱼是星甲鱼的近亲
A small pocket of fish, relatives of Astraspis,
它们进化出了一种很独特的特征
have developed a unique trait,
一副能活动的双颚
movable jaws.
这种鱼叫做刺鲛
They are called Acanthodians.
它们会聚集到任何有动物残骸出现的地方
They swarm anywhere there's a carcass.
这种新的变化使它们能够咬下猎物的肉
Their new adaptation allows them to nibble flesh off prey,
而不需要等食物碎屑漂来
instead of waiting for morsels of food to float by.
鱼类一开始时是吸食水藻的低等动物
From their humble beginnings as algae suckers,
而现在鱼类开始在食物链上逐渐爬升
fish are now moving their way up the food chain.
大灭绝把胜利者变成失败者 把被捕食的对象变成掠食者
Mass extinction transformed winners into losers, the hunted into hunters.
虽然角色不同了 但是生老病死的循环却一直没有停过
Different roles, but the cycle of life and death continues.
生命会一直持续下去
Life will continue.
伽马射线大爆发至今已经过去300万年了
It is now 3 million years after the gamma ray burst,
热带温室气候重临地球
Earth returns to a tropical greenhouse climate.