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I'm on a fantastic journey to look for the origins of life.
我在这个探索生命起源的奇妙旅途中。

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I shall be travelling not only around the world, but back in time,
我不仅要游览世界各地，而且我要回到过去。

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to try and build a picture
试着呈现一幅，

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of what life was like in that very early period.
最初生命的画面。

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It will be a journey full of wonders。
这将是充满奇遇的旅程。

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Parts of it were unknown until only a few years ago.
直到几年前，人们才知道它们的存在。

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In 50 years of programme-making,
在50年的节目制作中，

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I've been lucky enough to explore the living world in all its splendour and complexity.
我非常有幸能够去探索这些奇妙复杂的生物。

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The blue whale! The biggest creature that exists on the planet!
蓝鲸！地球上现存最大的动物！

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Now, I'm off to explore the origins of all this.
现在我将启程去探索这些生物的起源。

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To look for the very first living creatures that appeared on the planet.
寻找最初出现在地球上的动物。

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In recent years,
scientists have unearthed dramatic evidence of what those first creatures were like.
近年来，科学家揭开这些生物的神秘面纱。

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We can also find clues in living animals.
我们也能从现代生物中获得线索。

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And this enchanting little creature
这个迷人的小家伙

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is what we were looking for.
就是我们一直在找的。

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Using the latest technology,
it's possible to bring those first animals to life
应用最先进的技术。使这些五亿年前的

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for the first time in half a billion years.
早期生物重新复活。

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From the moment they appeared
从它们出现的那一刻

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to the time that they took their pioneering steps on land,
直到它们开始登上陆地

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we can deduce how animals acquired bodies that move,
我们可以演绎出动物是怎样具有移动的能力。

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eyes that saw and mouths that ate.
有视觉功能的眼睛和有取食功能的的口。

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And we can understand how those first organisms
同时我们可以理解，

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laid the foundations for modern animals as we know them today.
最早的生物体已经为我们所熟知的现生生物奠定了基础。

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Hello, old boy. How are you?
你好，兄弟，你好吗？

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Including you and me.
包括你我在内。

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My 40,000 mile journey begins very close to home, in Britain.
我的40 000英里的旅行始于我家乡英国附近。

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This is the Charnwood Forest in Leicestershire in the middle of England.
这是Charnwood森林位于英国中部的Leicestershire州。

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As a schoolboy, I grew up near here.
在这里，我度过了我的学生时代。

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And in these rocks,
在这些岩石中，

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a discovery was made that transformed our understanding
取得了重大的发现

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of that mystery of mysteries，the origin of life.
改变了我们对生命起源之谜的理解。

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The history of life can be thought of as a many-branched tree,
生命的历史可以认为是一棵有很多分叉的树。

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with all the species alive today
其中我们现生生物

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related to common ancestors down near the base.
树干代表的古老的祖先。

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The five kingdoms of life, the main branches, were established early on.
生命的五界系统，在初期早已建立了。

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Bacteria.
原核生物界 如 细菌

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Protists - amoeba-like creatures.
原生生物界 如 变形虫

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Fungi.
真菌界

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Plants.
植物界

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And animals。That for me is the most fascinating question of all.
以及动物界。这对我来说这是最有吸引力的

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How and when did they first appear?
它们是何时以及怎样出现的？

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The answers are only now beginning to emerge -
答案现在才显现出来

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and some of the first clues came from here in Charnwood Forest.
最初的线索来源于Charnwood森林里。

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I was a passionate fossil collector.
我是个化石收藏迷。

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But I never came to look for them in this part of Charnwood,
但是我从未在Charnwood的这个地区寻找化石

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because the rocks here are among the most ancient in the world.
因为这里的岩石在最古老的岩石之中。

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Around 600 million years old,in fact.
实际上有6亿年的历史。

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And every geologist knew or at least was convinced that rocks of
每个地质学家知晓或者确信

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such extreme age couldn't possibly contain fossils of any kind.
如此极端的年龄的岩石中不可能找到任何化石

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And then a boy from my very own school,
just a few years after I left it,
之后，一个同校的男孩在我离校后的几年

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made an astounding discovery.
有了惊人的发现。

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Against all the predictions of scientific know-alls,
这个发现与之前的科学常理的推论相违背，

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he found a fossil in these ancient Leicestershire rocks.
他在Leicestershire的这些古老的岩石中发现了化石。

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And this is it.
这就是它。

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It's called and is known around the world as Charnia,
他被称为世界有闻名的Charnia

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after the forest in which it was discovered.
化石在森林里被发现后。

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But what is it?
但是，它是什么生物？

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Is it animal or plant?
是动物还是植物？

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The fact is it comes from such a remote period
实际它们来源于非常遥远的年代

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that the distinction between those two forms of life was not yet clear.
这两种形式的生命体之间的界限尚不清晰。

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But one thing is certain.
但是一件是确定的。

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It clearly was alive.
它们显然是活物。

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Charnia was a marine organism,part of an ancient community
Charnia是一种生活在远古海洋的生物群落的一员

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of living things that lived in darkness at the bottom of an ocean.
它生活在黑暗的深海。

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That much we do know.
我们知道的仅仅如此。

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But what was this strange creature?
但是这是一种什么样的奇特生物呢？

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When did it first appear?
它何时出现的？

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And how is it related to modern animals?
它与现生生物有什么关系？

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The answers to these questions are only now beginning to emerge.
这些问题的答案最近才浮现出来。

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There were further finds in Charnwood forest, like this disk,
Charnwood森林中的研究有许多新进展 

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which was probably the holdfast
例如这个盘状的很可能Charnia用来

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which secured the frond of Charnia to the sea floor.
固定在海底的吸盘

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And then people began to look in rocks of this great age
之后全世界的人们

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all around the world.
开始关注这段特别的时期。

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And lo and behold they discovered
a whole range of fossils
通过研究它们的一系列的化石的组合

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that enable us now to put together
in extraordinary detail
使得我们今天能够

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the first chapters in the history of life.
了解到生命史诗初章的细节。

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That all happened a very long time ago.
这些都发生在遥远的时代。

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Imagine travelling back through time.
试想时光倒流。

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Humans have been around for two million years.
人类已经生存了200万年。

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The dinosaurs were wiped out 65 million years ago.
恐龙在6500万年前灭绝了。

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Charnia is more than eight times older than the oldest dinosaur.
Charnia 比最古老的恐龙还要老八倍。

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It lived about 560 million years ago.
它生活在5.6亿年前。

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But compared with the age of life itself, that's nothing.
但是比起生命史的年龄这不算什么。

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Before Charnia and other complex organisms existed,
在Charnia之前有许多其他复杂的生物。

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the only living things were microscopic single cells.
唯一发现的生物是单细胞的。

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They first appeared about three and a half billion years ago。
它们最初出现在35亿年前

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when the Earth was a very different place.
当时的地球与现在十分不同。

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The early continents were still forming.
早期的陆壳尚在形成中

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The days were a mere six hours long,
一天仅仅6个小时

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because at that time the Earth was spinning much faster on its axis 
than it does today.
当时地球的自转周期比现在要快得多。

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The land was dominated by volcanoes -
陆地上满是火山

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hostile and lifeless.
荒芜且毫无生气。

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But deep in the oceans,life had begun.
但是在海洋深处，生命开始诞生。

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The latest theory is that chemicals spewing from underwater volcanic vents
最新的理论认为各种化合物从水下火山喷涌而出

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solidified and created towers like these,
化合物结合后形成这种塔状结构，

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and this produced the conditions needed for the first cells to form.
它们为早期生物形成提供温床。

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Some of these began to harness the energy of sunlight, 
just as plants do today, and formed colonies.
它们中的一些像植物一样开始利用光能，并聚集成群 。

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These rocky stromatolites in western Australia
这些是澳大利亚的叠层石

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have been constructed by very similar photosynthesising bacteria.
它们是由简单的光合细菌构成的

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Others managed to survive by extracting nourishment directly from the environment, 
其他的设法通过直接吸收外界营养物质生存下来，

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like the fungi and animals that would later evolve.
例如真菌类和动物这些是后来演变的。

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This state of affairs continued for a vast period of time.
这种状态维持了很长一段时间。

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For some three billion years, simple microscopic organisms
这些三十多亿年前的简单的微生物

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were the most advanced form of life on the planet.
是当时地球上最先进的形式了。

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That's way over half the entire history of life on Earth.
它们维持了地球生命历史一半的时间。

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And then suddenly, within the space of a few million years, a mere
在几百万年间 虽然只是漫漫演化历程的眨眼间

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blink of the eye in evolutionary terms, advanced organisms appeared.
更高等的有机体出现了。

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Why is a mystery！
至于为什么，还是个迷！

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but we may find some clues to it on the coastline down here.
但是我们可以在这里的海岸线上找到线索。

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On the Eastern coast of Canada,
在加拿大的东海岸，

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there is evidence of an event 
that may well have been the spark that started the evolution of animals.
存在一些可能是引发了动物演化事件的因素。

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These rocks have been dated by radioactivity
这些岩石曾被用来检测地质年代

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to just before the moment that life became very complex.
正是在在动物刚刚变得复杂之前的的年代

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So if we can understand the circumstances under which these rocks were formed,
因此如果我们能够了解形成这些这些石头的环境因素

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we may get a clue as to why it was that life suddenly became more complex.
那么我们可能找到线索解释 这些复杂生命突然出现的原因

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Fragments of red stone are embedded in the darker rock.
红色石头的碎片嵌入在较暗的岩石中

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They look out of place.
它们像是不速之客

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And, in fact, they are.
事实上它们的确如此

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Geologists call them drop stones.
地质学家称它们为 落石

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They were transported here by glaciers.
它们被冰川搬运到这里

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As the ice moved off the land,
当冰川离开陆地

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it floated out over the sea in a great shelf,
就像是漂浮在海面上竹筏

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carrying with it stones that it had gathered on the continents.
运送着在陆地上携带的碎石

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And when the ice eventually melted,
但是当冰川最终融化后

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the stones fell into the sediments on the sea floor.
碎石落入海床的沉积物中。

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This wasn't the only place covered by ice.
曾经这里不是唯一被冰雪覆盖的地方。

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Drop stones of the same age have been found in deposits all over the world.
同一时代的落石（冰碛岩）全球都有发现。

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The evidence points to a global spread of glaciation.
这是全球性的冰期的证据。

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Just before complex life appeared,the world was in the grip
在复杂生物出现以前，

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of the biggest ice age in its entire history.
地球正处于整个历史中最大的一次冰期期间。

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It's been called Snowball Earth.
被称为雪球地球。

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The Earth was plunged into a deep freeze
地球陷入极度地寒冷

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so severe it probably extended
因此

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from pole to pole.
几乎延伸到两极

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The surface of the seas were frozen over.
海洋表面都被冻结。

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On the continents, ice caps and glaciers developed.
在陆地上，发育着冰盖和冰河

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In places, the ice was probably a kilometre or so thick.
在某些地方，冰层可能厚达一公里或更甚

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We still don't know enough about the details, but it's likely that
我们无法得知更多的细节

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00:11:59,840 --> 00:12:03,400
those conditions lasted for millions of years.
但是这种情形似乎持续了一百万年

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Stromatolites and similar bacterial colonies that dominated the Earth
随着冰期的发展 

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were crushed under the advancing glaciers.
叠层石和类似菌落主宰地球的情形被瓦解了

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Life was nearly annihilated before it had truly begun.
生命的萌芽几乎被彻底扼杀了

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It's difficult to imagine how life managed to survive in those circumstances.
很难想象在这种情况下生命能够存活下来

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But survive it did.
但是它们存活下来了。

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00:12:42,120 --> 00:12:44,680
Microbiologist Dr Hazel Barton
微生物学家Hazel Barton博士

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believes that modern glaciers can tell us how it did so.
认为现代冰川能够解释这个问题。

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She has come to the Columbia Icefield in the Rocky Mountains
她已经来到Columbia洛矶山脉的冰原

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in search of organisms that are still able to endure such extremes today.
寻找能够忍受现今极度寒冷的生物。

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The thing about being here
那种生物在这里

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is it looks like everything's been wiped clean,
看起来任何东西都被擦的一尘不染

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the glacier's come through and it's destroyed all life,
冰川的到来使得生物遭到重创，

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there's nothing living.
这里毫无生气。

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But to a microbiologist this looks a bit like a rainforest.
但是微生物学家把这里看为热带雨林。

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From here you can see discolouration on the surface of the ice,
冰川的表面你能看见染色

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but that's not dirt -
但是这可不是脏东西

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that is photosynthetic bacteria that are surviving there
那是生存在上面的光合细菌

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and that creates an ecosystem where you have plants
它们创造了一个生态系统 

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and you have predators come in and feed on those organisms.
有了植物从而有了吃它们为生的动物。

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So even though it looks dead，it's actually wildly alive with life.
因此，即使看似死寂沉沉的地方，实际充满着生命。

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The kind of life you can see here is pretty ancient.
你在这里看到的这种生命是相当古老的。

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They've had to adapt to a lot of global catastrophes.
它们已经适应了全球性的灾变。

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They had to adapt to Snowball Earth.
它们必须适应雪球地球的环境。

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Microorganisms that live in these harsh environments we call extremophiles.
在这种极端环境中生存的微生物被称为极端环境微生物。

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They have an amazing amount of adaptability that's hardwired in their genomes.
它们的基因组中含有大量克服极端条件的遗传密码。

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You can freeze them, you can bury them a mile down in ice
你可以冰冻它们，你也可以把它们埋在厚达一英里的冰川里

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and its not much of a hindrance because of their adaptable nature.
它们毫发无损 因为它们能够适应环境。

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We owe our existence to ice-dwelling extremophiles.
我们的存在归功于冰期这种极端环境。

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Snowball Earth almost extinguished life,
雪球地球几乎熄灭了生命之火。

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but tiny organisms like these hung on for millions of years.
但是一些像这样的小生物坚持了几百万年。

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I think what you had is
我想正是这些

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organisms that could withstand extreme environments
经得起极端环境的考验的生物

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conditioning themselves to this changing ecosystem.
改变了生态系统。

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You had a skin of microbes on the surface of the planet,
在地球的表面有一微生物层

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and you had these organisms living between where the, 
the glaciers contacted the rock,
它们生活于冰川携带的岩石之间

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and that was enough life trickling over so that
那里有大量生生不息的生物

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when those conditions retreated，and it became more favourable,
因此 当那些环境开始恢复且变得更加适应

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then it was like, peng，and everything took off again.
之后 嘭 所有的生物重新开始

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Finally,Snowball Earth began to warm.
最后，雪球地球开始变暖了。

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There is evidence that around this time,
这里有那时的证据，

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there was a global surge in volcanic activity.
当时是个较剧烈的全球性火山活跃期。

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Eruptions punched through the ice，
spewing carbon dioxide into the air.
爆发的岩浆向冰川砸去，并且向空气中释放二氧化碳。

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As it spread through the atmosphere，
it produced a greenhouse effect,
并且它在大气中扩散产生了温室效应，

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trapping heat so that the earth warmed and the ice melted.
被热量笼罩下的地球变得温暖，冰雪消融了。

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We still have a lot to discover about what happened next,
我们有很多发现关于接下来发生的事情，

186
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but it seems likely that it was the melting of Snowball Earth
但是似乎在雪球地球融化之时

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that led to the next great development of life.
生命得到进一步演化。

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As the glaciers retreated,
当冰川渐渐消退，

189
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so nutrient-rich meltwater flooded into the oceans.
冰川融水带着大量养分流入海中。

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For the surviving cells,this flood of ground-up rock was a bonanza.
对于活细胞来说，这些涌入水中的岩石碎屑是矿物源。

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For the microbes that could photosynthesise,
对于那些光合细菌等微生物来说，

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the pulverised rock was a potent fertiliser.
岩石粉末是高效的化肥。

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And their growth would have a direct influence on early animal cells.
并且微生物的增加直接影响了早期动物的细胞。

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Cyanobacteria and other oxygen-producing microbes
蓝藻和另外的一些生产氧气的微生物

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began to bloom across the globe.
开始在全球繁盛起来。

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These flourished in colonies of plant-like microbes
植物性的微生物群落开始繁盛

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that pumped out enormous volumes of oxygen.
使得氧含量剧增。

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And it was this increase in oxygen
氧含量的增加

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that was the key to the rise of the animal kingdom.
是动物王国崛起的关键。

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Now, simple microscopic life
现在，简单的微生物

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had the fuel it needed to develop into something bigger.
具有使它们变得更大的养料。

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After billions of years of single-celled life,
经过十亿年的单细胞生命后，

203
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something amazing happened in the deep sea.
在深海中发生了一些惊奇的事情。

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Up to this moment, living cells that had been produced by division
到目前为止，

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simply drifted away from one another.
细胞通过向两端分裂来复制。

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But now，with the aid of increased oxygen,
但是现在，氧含量的增加，

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some cells were sticking together.
一些细胞粘合在一起。

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Some of these clumps ultimately evolved into animals.
这些细胞群最终演化为动物。

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To find out how oxygen drove this process,
为了查明氧气如何启动这个程序，

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I have come to Australia's Barrier Reef,
我来到了澳大利亚的大堡礁，

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to look at one of the most primitive of animals alive today -
去看看那些存活至今的原始生物中的一员

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one that can truly be called a living fossil.
一类货真价实的活化石。

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It is one of the simplest multi-celled organisms that we know,
它是我们所知的多细胞生物中最简单的类群之一

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but its basic body structure has nonetheless enabled it
但是它身体的基本结构

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to survive virtually unchanged for around 600 million years.
在经历了6亿年后依然没有什么变化。

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It's a sponge.
正是海绵。

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Sponges are just collections of simple cells
海绵动物是单细胞的聚合体

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that have clumped together and got stuck together.
它们聚结且互相粘附着。

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They don't have a digestive system or a nervous system
它们没有消化系统或者神经系统

220
00:18:57,440 --> 00:18:59,560
or a blood circulatory system,
或者血液循环系统

221
00:18:59,560 --> 00:19:02,120
and they get their food and their oxygen
它们让海水泵入身体的沟系中

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00:19:02,120 --> 00:19:07,520
by just pumping seawater through channels in the body.
来取得食物和氧气。

223
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But they can give us an indication of how it was that cells
但是它们能够给我们一些启示

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first clumped together to form bodies of any real size.
这些细胞首先聚合在一起形成任何大小

225
00:19:19,320 --> 00:19:22,800
At the microscopic level,sponge cells are bound together
在显微镜下，通过凌乱的纤毛与由纤维蛋白分子组成的胶原

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by a tangle of hairy, stringy protein molecules called collagen.
使得海绵细胞紧密地结合在一起。

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00:19:29,840 --> 00:19:35,320
This collagen glue is found only animals, and nowhere else.
这种胶原蛋白胶只存在于动物中。

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Collagen is sometimes called the sticky tape of the animal world.
胶原蛋白被称为动物世界的胶带。

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It's the commonest protein in our body.
它是我们身体中最常见的蛋白。

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It forms the framework of our skins.
它形成了我们皮肤的框架。

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Plastic surgeons use it to pump up our lips.
整形外科医生用它们充进我们的嘴唇。

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You need oxygen to manufacture collagen.
你需要氧气制造胶原。

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and with the rising amount of oxygen in the atmosphere
在大气氧气含量升高期间

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at the end of Snowball Earth，
cells were able to manufacture it.
也是雪球地球的结束时期。细胞能够生产胶原了。

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00:20:07,240 --> 00:20:11,040
At the Research Station on Heron Island on the Great Barrier Reef,
在位于大堡礁的Heron岛的一个研究站中

236
00:20:11,040 --> 00:20:13,320
scientists are working to understand
科学家在研究

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00:20:13,320 --> 00:20:16,800
how it was that multi-celled organisms
多细胞生物是怎样

238
00:20:16,800 --> 00:20:18,640
began to colonise the earth.
开始开拓地球的。

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00:20:19,440 --> 00:20:23,920
To find the answer, marine biologist Professor Bernard Degnan
为了找到答案，海洋生物学家Bernard Degnan教授

240
00:20:23,920 --> 00:20:27,120
is studying sponges.
致力于海绵的研究

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00:20:27,120 --> 00:20:30,560
The things that connect sponges to the rest of the animal kingdom.
一样东西让我可以从海绵联系到整个动物世界。

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we can find at the level of the cell and the gene.
从细胞水平到基因水平

243
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When we look at its genes,
it's clearly an animal.
当我们看到它的基因时 它显然是个动物

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We look for the things that bind all animals together,
我们寻找能够在所有动物中通用的

245
00:20:42,000 --> 00:20:45,520
so what does a human share not only with a chimpanzee
因此人类不仅仅与黑猩猩及

246
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and for that matter a tiger but what it shares with a sponge.
老虎具有相似的遗传密码，但是和海绵呢。

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If we can find any common threads,
如果我们能找到通用的密码，

248
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we're getting really to the heart of the matter of multicellularity in the animal kingdom.
我们就能够找到多细胞动物起因。

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so that's the key.
因此这就是关键。

250
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A classic experiment gives us some insight.
一个经典的实验给我们更深刻的理解。

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First, a spongeis cut into small pieces.
首先，一个海绵被切碎，

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Then it is pushed through a sieve on the end of a syringe.
之后，放入筛口注射器中被挤出来。

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This breaks the animal down into its individual cells.
把这个动物分离为单细胞。

254
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This may seem a brutal thing to do to a living organism,
对这个生物如此貌似很残忍，

255
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but to a sponge this is of no consequence.
但是对于海绵来说可不一定。

256
00:21:39,760 --> 00:21:44,880
In response,it does something quite astonishing.
它的反应非常让人震惊。

257
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The cells begin to move...
这些细胞开始移动...

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and then they form clumps.
并且聚集成团。

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Soon the clumps form bigger clumps,
不久团块越来越大，

260
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until three weeks later,a miniature sponge has formed.
到三周后，小海绵形成了。

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Sponges have this amazing capacity to regenerate themselves.
海绵具有惊人的再生能力。

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And what we can do is actually rebuild a sponge
我们能做的是

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from the cell level up.
让海绵从细胞水平上再生。

264
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From this experiment,we can maybe infer a few things
从这个实验中 我们能够得到一些推论

265
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that happened 600 million years ago with the very first animals.
在6亿年前的最早期的动物

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We can infer that there were cells coming together,
我们可以推测它们的细胞聚集在一起，

267
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they could adhere to each other,they used extracellular proteins
它们可以互相粘附，利用细胞外面的蛋白

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like collagen to glue themselves together.
就像胶原蛋白把它们自己粘合在一块。

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They had the ability to communicate with each other
细胞之间可以相互交流

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and a certain amount of flexibility that allowed them to interact
变得更加柔韧

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to give rise to something that's bigger and greater,
因此可以使它们自己变得越来越大，

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a large macroscopic multicellular animal.
一个肉眼可见的多细胞动物。

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The advantages of being multi-celled were many.
多细胞的好处相当多。

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Colonies of cells could collect more food,
细胞群体可以收集到更多的食物，

275
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control their internal environment
改变它们内部的环境

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and act efficiently by working as a team.
团队工作更加有效率。

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It was just the beginning.
这只是刚刚开始。

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In Canada,there is an extraordinary place
在加拿大,这里有个特别的地方

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that reveals what happened next.
这将呈现下面发生的事情

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Here you can see how just a few million years after the melting of Snowball Earth,
在这里你可以看见雪球地球融化后的几百万年

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00:23:30,440 --> 00:23:35,240
the earliest multi-celled organisms became much more sophisticated...
最早的多细胞生物已经变很精密了...

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and much bigger.
并且更加大。

283
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This is Mistaken Point in Newfoundland.
这是纽芬兰的 错点

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It got that name because in years gone by sailors coming up the eastern coast of North America
这个名字是因为北美东海岸的水手来到这里

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but lost in the fogs that are so frequent here
但是迷失在忽隐忽现的浓雾中

286
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would head north for the open ocean
它们掉转船头往北方开去

287
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but be wrecked on these savage rocks.
但是却撞在坚硬的岩石上。

288
00:23:59,640 --> 00:24:05,960
But today Mistaken Point has a completely different reputation.
但是如今的错点的名声不同于从前。

289
00:24:05,960 --> 00:24:07,960
Today it is recognized as one of
现在它被认为是

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00:24:07,960 --> 00:24:13,120
the most important fossil-bearing sites in all the world.
世界上具有最重要的标本的化石点之一。

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00:24:13,120 --> 00:24:17,000
For here you can see fossils
在这里你可以看到最早动物

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of the very first animals that evolved on this planet.
出现在地球的化石证据。

293
00:24:36,400 --> 00:24:41,360
The fossils in these rocks are both wonderful and bizarre.
化石所在的岩石非常奇特且令人惊讶。

294
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When the sun is low in the sky,
当太阳以低角度的光线射过来时，

295
00:24:47,200 --> 00:24:51,160
the slanting light shows up their structure in great detail.
使这些化石的结构显示到极致。

296
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Organisms were no longer
生物体不再只是像海绵一般

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00:24:56,960 --> 00:25:01,000
just clumps of undifferentiated cells, like sponges.
毫无分化仅是一直聚集变大。

298
00:25:01,000 --> 00:25:05,280
They were organized into defined shapes.
它们组成清晰的形态。

299
00:25:05,280 --> 00:25:09,520
And among them are some that look exactly like Charnia
在它们中像Charnia的生物

300
00:25:09,520 --> 00:25:13,320
that had been first recognised in Charnwood Forest.
就是那些最先被发现于Charnwood森林中的化石。

301
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Here, there are not only hundreds of examples of Charnia,
在这里 不仅有许多Charnia，

302
00:25:19,520 --> 00:25:22,800
but a whole community of other strange creatures.
而且在这整个群落中许多其他的奇特生物。

303
00:25:22,800 --> 00:25:27,880
Everywhere you look there are complex markings and indentations 
这里遍地都是复杂的凹陷纹理

304
00:25:27,880 --> 00:25:29,400
of one kind or another -
是另一种生物留下的

305
00:25:29,400 --> 00:25:33,600
it's almost as though children have been playing in wet sand.
这和孩子们在潮湿的沙子上嬉戏留下的痕迹。

306
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It's like walking through a carpet of ancient creatures.
像是远古生物在地毯山留下的足迹。

307
00:25:37,840 --> 00:25:42,800
It's difficult to imagine that 565 million years ago
真是难以想象在5.65亿年前

308
00:25:42,800 --> 00:25:45,760
this was the bottom of the ocean
这里曾经是海底

309
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and these were some of the first animals to live on this planet.
这里曾是地球上最早的动物的家园。

310
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Here at Mistaken Point,
这里是 错点，

311
00:26:07,440 --> 00:26:11,320
exceptional conditions have preserved these delicate life forms.
特殊的环境使这些生物精巧地保存下来了。

312
00:26:16,720 --> 00:26:19,720
Each one of these layers of rock
这些岩石中的每一层

313
00:26:19,720 --> 00:26:24,080
was once mud lying at the bottom of an ocean.
曾经是海底的泥质层。

314
00:26:25,960 --> 00:26:29,600
An ocean so deep it was very cold,
这里很深所以非常寒冷，

315
00:26:29,600 --> 00:26:31,680
and very poor in oxygen,
非常缺氧，

316
00:26:31,680 --> 00:26:36,720
so any organism that died here took a very long time to decay.
因此，死于这里的生物需要很长时间才能被分解。

317
00:26:36,720 --> 00:26:40,120
But those that did have been preserved
但正因如此

318
00:26:40,120 --> 00:26:43,920
with an astonishing degree of perfection.
这些生物才能以让人惊叹的完美保存下来。

319
00:26:43,920 --> 00:26:46,640
What makes this place so different?
为何此地如此奇异呢？

320
00:26:50,800 --> 00:26:55,160
There was a volcano rising from the sea floor close by,
这附近有从海底升起的火山，

321
00:26:55,160 --> 00:26:58,480
and it spewed out millions of tons of ash.
从它那里喷涌出数百万吨的火山灰。

322
00:27:09,440 --> 00:27:11,480
The ash sank to the bottom,
火山灰沉入海底，

323
00:27:11,480 --> 00:27:15,520
blanketing everything like a sub-marine Pompeii.
正如庞贝城一样覆盖所有的地方。

324
00:27:17,040 --> 00:27:22,560
Over millions of years, the ash itself was buried by muddy sediments
数百万年后，火山灰又被泥质沉积物覆盖

325
00:27:22,560 --> 00:27:25,320
and then all was turned into rock.
之后一切变成了岩石。

326
00:27:25,320 --> 00:27:28,520
And then, over hundreds of millions of years,
又经过了几亿年的时间，

327
00:27:28,520 --> 00:27:32,000
mountain-building forces thrust the whole sea-floor upwards
造山运动把整个海底上推到

328
00:27:32,000 --> 00:27:35,200
to its present position on the coast of Canada.
加拿大沿海的现在这个位置。

329
00:27:38,120 --> 00:27:42,960
Dr Guy Narbonne is a world expert on the fossils of Mistaken Point.
Guy Narbonne博士是研究Mistaken Point的化石的世界级专家。

330
00:27:45,160 --> 00:27:48,520
What you can see on this surface？
在这个表面你能够看到什么？

331
00:27:48,520 --> 00:27:52,800
is the grey is the muddy sea bottom
灰色的是海底的泥质物

332
00:27:52,800 --> 00:27:55,960
and this is where the creatures all lived.
这儿曾是那些是生物栖息之地。

333
00:27:55,960 --> 00:28:01,880
And they were knocked down and covered by a bed of volcanic ash.
它们并被一层的火山灰击落并覆盖。

334
00:28:01,880 --> 00:28:06,320
And you can see it here and all of this pink and white
你能看这里有斑点状的粉色和白色的

335
00:28:06,320 --> 00:28:09,240
speckled stuff is volcanic ash.
是火山灰。

336
00:28:09,240 --> 00:28:12,880
The volcanic ash cast every part of them,
火山灰落得它们满身都是，

337
00:28:12,880 --> 00:28:16,640
like putting plaster around your arm if you break it,
就像是在手臂上帮着石膏一样，

338
00:28:16,640 --> 00:28:20,960
and that led to a perfect preservation
如果你破开

339
00:28:20,960 --> 00:28:23,480
of every detail of the outside.
它们外部的每一个细节都完美地保存下来了。

340
00:28:25,520 --> 00:28:29,080
Radioactivity in this light-coloured ash layer
Guy Narbonne通过浅色火山灰中的放射性检测

341
00:28:29,080 --> 00:28:33,120
allows Guy Narbonne to date precisely the eruptions,
能够得知火山爆发精确的时间，

342
00:28:33,120 --> 00:28:35,760
and therefore the fossils.
从而得知化石年代。

343
00:28:35,760 --> 00:28:40,360
Some are as old as 579 million years.
一些数据显示达5.79亿年.

344
00:28:40,360 --> 00:28:44,720
Here we can see one of the best of the fossils on the surface.
这个表面有一块保存最好的化石。

345
00:28:44,720 --> 00:28:50,680
It consists of disks,and they all have these pustules
它含有一个盘状物 它们满身是丘状物的隆起

346
00:28:50,680 --> 00:28:55,080
on them and that's why we rather affectionately call them pizza disks.
因此我们宁可称它们为比萨盘。

347
00:28:55,080 --> 00:28:58,880
And they were very simple in form,
它们外形很简单，

348
00:28:58,880 --> 00:29:03,800
but the first truly large creatures in Earth evolution.
但它们是地球演化史上最早的真正大型的生物

349
00:29:06,160 --> 00:29:10,240
The pizza discs are only one of the species found here.
比萨盘不是发现于这里的唯一的生物。

350
00:29:13,320 --> 00:29:18,640
Most are fern-like fronds, like this enormous species of Charnia.
更多的是羊齿叶状的，像Charnia这种巨型种类。

351
00:29:21,360 --> 00:29:23,760
This is a two-metre-long frond.
长达两米的叶状体。

352
00:29:23,760 --> 00:29:26,800
Astounding！And this is not the biggest.
太吓人了！这不是最大的。

353
00:29:26,800 --> 00:29:29,480
We have about 200 specimens of this here.
我们在这里发现了200种。

354
00:29:31,680 --> 00:29:35,760
The frond of Charnia found in Charnwood was isolated.
Charnia 的叶状体被发现是分离的。

355
00:29:37,360 --> 00:29:43,760
But here at Mistaken Point,
a whole community of organisms has been preserved together...
但是在 错点 ，整个群落被原地保存下来了...

356
00:29:43,760 --> 00:29:48,160
and that could give us new information.
因此给了我们更多新的信息。

357
00:29:48,160 --> 00:29:52,800
You're calling this an animal but is it justified to call it an animal?
你称它们是动物，但是它们被证实是动物吗？

358
00:29:52,800 --> 00:29:54,680
Well... It's rather plant-like.
它们并不像植物。

359
00:29:54,680 --> 00:29:57,960
Well, "What is it？"is a big question.
那么，它是什么呢？ 这可是个难题。

360
00:29:57,960 --> 00:30:00,560
We know for a fact it can't be a plant
事实上我们只知道它们不会是植物

361
00:30:00,560 --> 00:30:03,640
because we're in water thousands of metres deep,
因为我们知道在千米深的海底，

362
00:30:03,640 --> 00:30:06,720
there wouldn't have been enough light to read a newspaper.
那里的光线不足以看清报纸。

363
00:30:06,720 --> 00:30:11,000
We're several orders of magnitude too little light for photosynthesis.
对于进行光合作用的生物来说几个数量级的光线是不够的。

364
00:30:11,000 --> 00:30:14,440
OK, so it's not photosynthesising because it's too deep
好吧、由于太深了所以它们不能进行光合作用

365
00:30:14,440 --> 00:30:17,360
and therefore it's not a plant.
What's it living on？
既然它们不是植物。那么它们以何为生呢？

366
00:30:17,360 --> 00:30:23,880
What we believe they're living on is dissolved carbon and other nutrients in the deep oceans.
我们认为它们以溶解碳和其他深海的营养物质为食。

367
00:30:23,880 --> 00:30:29,480
So it's absorbing these nutrients through its entire body.
因此它们用全身吸收这些营养物质。

368
00:30:29,480 --> 00:30:34,880
Very thin. Probably not much thicker than your thumbnail.
非常薄的体壁。不及你指甲的厚度。

369
00:30:34,880 --> 00:30:37,160
Very primitive.
非常原始的类群。

370
00:30:39,400 --> 00:30:43,880
These organisms were very simple animals.
这些生物是非常简单动物。

371
00:30:43,880 --> 00:30:49,440
Beyond the reach of light，
they had to survive by absorbing chemical sustenance.
超越阳光所及的深度，它们能吸收化学营养生活。

372
00:30:49,440 --> 00:30:54,320
But most animals we know today are able to move about.
但是我们所知的现生大部分动物是可以移动的。

373
00:30:54,320 --> 00:30:58,520
Even sponges and corals have swimming larvae.
即使是海绵和珊瑚都有可游动的幼虫。

374
00:30:58,520 --> 00:31:01,400
But there's no evidence of that here.
但是这里没有任何证据。

375
00:31:03,160 --> 00:31:06,840
The creatures were all immobile.
这些生物固着的。

376
00:31:06,840 --> 00:31:08,680
Nothing could move.
都是不能移动的。

377
00:31:08,680 --> 00:31:10,880
Nothing had a mouth,
都没有口，

378
00:31:10,880 --> 00:31:13,400
nothing had muscles.
也没有肌肉。

379
00:31:14,920 --> 00:31:17,440
Probably none of them had colour,
很可能它们没有什么颜色，

380
00:31:17,440 --> 00:31:21,520
probably an eerie whiteish colour to everything.
但也很可能各种奇特的颜色。

381
00:31:23,560 --> 00:31:29,040
These are the oldest large multi-cellular creatures on Earth,
这是地球上最早的大型多细胞生物，

382
00:31:29,040 --> 00:31:32,680
the oldest things that might be called proto-animals.
最古老的因此被称为先驱-动物。

383
00:31:34,200 --> 00:31:38,280
This is not like anything that exists on earth today.
这些与如今地球上现生的毫不相像。

384
00:31:38,280 --> 00:31:41,600
Even though they're not directly related to us,
即使它们与我们没有直接的关系，

385
00:31:41,600 --> 00:31:47,320
like some distant relative,
they provide us with a view of our own beginnings.
像是我们的远亲，它们为我们起源问题提供了一种观点。

386
00:31:50,920 --> 00:31:55,480
One of the most peculiar things about these wonderful proto-animals
在这些奇特的生物中有一个最奇妙的事情

387
00:31:55,480 --> 00:31:58,440
is the way they constructed their bodies.
就是它们建立自己身体的方式。

388
00:32:00,360 --> 00:32:05,280
Unlike modern creatures，
they had a very simple pattern of branching.
不同于现代的生物，它们以简单的分支的方式成长。

389
00:32:10,120 --> 00:32:14,280
Despite their size，these are still very simple animals.
它们虽然很大，但却是非常简单的动物。

390
00:32:14,280 --> 00:32:18,360
They can be put together with just six to eight genetic commands,
它们能够以6-8个遗传指令自我组装起来，

391
00:32:18,360 --> 00:32:25,520
as against some 25 000 such commands that were needed to construct a mammal like me.
对于像我这样的哺乳动物来说需要25000个指令。

392
00:32:25,520 --> 00:32:28,040
You can see this if you look at them in detail.
如果你观察它们的细节你会发现。

393
00:32:28,040 --> 00:32:31,840
You see that they are made up of a series of very small modules
它们由许多一系列很小的单元组成

394
00:32:31,840 --> 00:32:35,640
which are attached to one another in a number of different ways.
每一个都以不同的方式连接着另一个上面。

395
00:32:37,320 --> 00:32:43,760
Their modular or fractal way of building their bodies 
is one of Guy Narbonne's main areas of research.
它们建立身体的的片状单元是Narbonne的主要研究方向。

396
00:32:46,080 --> 00:32:50,000
His study is centred on one particular species.
他重点研究了其中一种特殊的种类。

397
00:32:51,560 --> 00:32:53,080
This is Fractofusus.
这是Fractofusus。

398
00:32:53,080 --> 00:32:56,040
It's the most common fossil in the Mistaken Point assemblage.
它们在错点的化石群体中最常见的。

399
00:32:56,040 --> 00:32:58,600
We have literally thousands of specimens.
我们发现了数千种这类生物的化石。

400
00:32:58,600 --> 00:33:01,640
And it would have lain on the sea bottom like you see there.
它们曾经生活在海底就是你现在看到的地方。

401
00:33:01,640 --> 00:33:05,520
A spindle-shaped mass, very thin.
它包含大量的梭形的单元。

402
00:33:05,520 --> 00:33:08,640
It consists of these elements.
它们非常地薄

403
00:33:08,640 --> 00:33:10,720
And there are 20 of them on either side.
左右各有20个单元。

404
00:33:10,720 --> 00:33:13,440
And if you look at an individual element,
如果你观察每一个单元，

405
00:33:13,440 --> 00:33:15,760
it's remarkably finely-branched.
它们是显然是分支形的。

406
00:33:15,760 --> 00:33:18,640
It's a style we called fractal or self-similar.
这种形式被称为分形或自相似性。

407
00:33:20,160 --> 00:33:24,280
These fractal organisms grew by repetitive branching,
这些片状单元组成的生物通过重复分支来变大，

408
00:33:24,280 --> 00:33:27,840
with each branch exactly the same as its predecessor
从微观层面上来说

409
00:33:27,840 --> 00:33:30,200
from the microscopic level upwards.
每一个分支实际上与它们的先辈完全一样。

410
00:33:32,760 --> 00:33:37,440
It was a simple, yet extremely，effective way of building a body.
它以非常简单且非常有效的方式来构建身体。

411
00:33:44,720 --> 00:33:50,320
Such finely-divided branches gave the organism a huge surface area,
由于有精细分支结构从而使得生物有巨大的表面积，

412
00:33:50,320 --> 00:33:55,480
and this allowed them to absorb nutrients directly
without mouths and without guts.
这使得它们无需口和消化道而直接吸收营养物质。

413
00:33:58,120 --> 00:34:02,160
This simple fractal body plan proved very successful.
这个简单的不规则的身体构型被证实十分成功的。

414
00:34:03,680 --> 00:34:09,080
So animals using it grew large for the first time 
in the history of life on Earth.
因此地球生命史的动物首次长得很大。

415
00:34:13,160 --> 00:34:19,720
Fractal design was perfect for getting these earliest creatures off and running
分形的设计对于早期的动物的启动是非常成功的

416
00:34:19,720 --> 00:34:21,800
and its easy to see why.
显然 原因是

417
00:34:21,800 --> 00:34:26,160
It takes a minimum of genetic programming in order to make one.
这种形式的生物只需最少的遗传基因便可完成。

418
00:34:26,160 --> 00:34:29,320
You could probably do it with six or eight codes in your PC
你很可能能够用6-8个计算机程序

419
00:34:29,320 --> 00:34:32,720
to make something that was fractally branching.
来完成这种分支结构。

420
00:34:32,720 --> 00:34:37,520
And then combining them to make up larger elements is literally  child's play,
然后 像玩儿童玩具一样把它们组装在一起

421
00:34:37,520 --> 00:34:43,560
like a toddler might take Lego blocks and put them all together 
in order to make up a larger structure.
正如蹒跚学步的孩子把小积木搭成更大的结构。

422
00:34:47,640 --> 00:34:54,920
The fossils of Mistaken Point provide a detailed record of fractal animals.
错点的化石是提供了分形动物细节的记录。

423
00:34:54,920 --> 00:35:00,040
But the absence of anything like them in more recent rocks is very significant.
但是重要的是在之后的岩石中却再也没有这类化石的发现了。

424
00:35:02,560 --> 00:35:07,720
Just a few million years after they first evolved, 
they vanished.
在它们刚刚开始演化后的几百万年后，它们就消失了。

425
00:35:09,240 --> 00:35:11,600
They have no living descendents.
没有它们活着的后代。

426
00:35:11,600 --> 00:35:14,280
They were an evolutionary dead end.
它们进入了演化的死胡同。

427
00:35:15,800 --> 00:35:17,480
And the reason?
是什么原因呢？

428
00:35:17,480 --> 00:35:21,280
The very simplicity of their fractal way of growing.
原因是最简单的分支型生长方式。

429
00:35:22,800 --> 00:35:30,120
They utterly dominate about the first 20 million years 
of the evolution of complex multi-cellular proto-animals.
虽然它们演变为复杂多细胞生物并且主宰最初2千万年的演化历史。

430
00:35:30,120 --> 00:35:34,320
However, this fast start was also their demise.
但是只是昙花一现。

431
00:35:34,320 --> 00:35:38,120
Because they were incapable of evolving things 
因为它们不能够演化出后来生物所具有的

432
00:35:38,120 --> 00:35:43,120
like guts and brains and muscles and teeth that later animals did. 
消化道、大脑、肌肉、牙齿。

433
00:35:45,920 --> 00:35:49,240
If animals were to acquire these things,
一旦动物获得了这些装备，

434
00:35:49,240 --> 00:35:53,640
they would have to build their bodies in a completely different way.
那么，它们将以完全不同的方式建立身体。

435
00:35:53,640 --> 00:35:58,440
And eventually, animals appeared that did exactly that.
最终，动物确实以那样出现了。

436
00:36:00,600 --> 00:36:05,120
To see them, 
I'm travelling south from Newfoundland across the equator
为了找到它们，我从纽芬兰的南部穿越赤道

437
00:36:05,120 --> 00:36:06,880
to South Australia.
来到了澳大利亚。

438
00:36:12,720 --> 00:36:15,320
The Ediacara Hills.
这里是Ediacara山。

439
00:36:17,560 --> 00:36:25,560
Here lie animals whose body plans are fundamentally the same as those of almost all animals alive today...
保存在这里的动物，它们基本的身体构造

440
00:36:25,560 --> 00:36:27,240
including us.
几乎与与包括我们在内的所有的现生生物一样。

441
00:36:29,800 --> 00:36:35,920
The creatures that are preserved here lived just after fractal animals began to die out.
保存在这里的生物生存于分形生物灭绝之后。

442
00:36:41,720 --> 00:36:48,840
And about 550 million years ago,
their differently-organised bodies gave them something quite new...
大约5.5亿年前，它们不同起源的身体构型能够给它们带来了很新的东西...

443
00:36:52,320 --> 00:36:53,840
mobility.
移动能力。

444
00:36:56,200 --> 00:37:01,320
But how and why did animals first begin to move？
但是这些动物是怎样为何能够移动呢？

445
00:37:01,320 --> 00:37:06,040
Scientists are beginning to find answers to those fascinating questions.
对于这些神奇的问题科学家们开始寻找答案。

446
00:37:06,040 --> 00:37:11,040
And much of the detail comes from these extraordinary fossils behind me.
更多的细节来源于我身后的这些非凡的岩石。

447
00:37:15,280 --> 00:37:20,600
A team of scientists, led by palaeontologist Dr Jim Gehling
由Jim Gehling带领的科考团队

448
00:37:20,600 --> 00:37:23,280
is uncovering the evidence in great detail.
揭示了更多细节的证据。

449
00:37:25,520 --> 00:37:27,880
When you have these beds covered in red clay
这层上被覆盖了红色的粘土

450
00:37:27,880 --> 00:37:31,880
you have a good chance of the beds having well-preserved fossils.
是的这个地层的化石能够很好地保存下来。

451
00:37:31,880 --> 00:37:34,800
This is the original sea floor.
这是原始的海床。

452
00:37:36,880 --> 00:37:42,160
And this sea-floor was very different from that in the deep waters of Mistaken Point.
这个海床与错点的深海海床完全不同

453
00:37:42,160 --> 00:37:44,360
This was once a shallow reef.
这曾经是浅水礁滩。

454
00:37:44,360 --> 00:37:47,120
It is 550 million years old.
有5.5亿年的历史了。

455
00:37:48,960 --> 00:37:53,360
The surface of the ocean floor was covered with organic ooze.
海底表面被有机软泥覆盖着。

456
00:37:53,360 --> 00:37:56,520
It may have even been green or orange. 
We don't know the colour.
它可能是绿色或是橘色，不清楚它当时是什么颜色的。

457
00:37:56,520 --> 00:38:03,560
But there was a lot of organic material made up by bacteria and all sorts of microorganisms.
但是这里有许多由细菌和各种微生物形成的有机质。

458
00:38:03,560 --> 00:38:10,480
But sitting in and amongst that garden of slime, 
we would have seen these strange creatures.
但是坐在花园的软泥中，我们将看见奇怪的动物。

459
00:38:13,560 --> 00:38:16,960
Jim Gehling's team is working to decipher the fossils.
Jim Gehling的团队是致力于研究这些化石。

460
00:38:16,960 --> 00:38:21,400
But it is not easy because these creatures still lacked any hard parts to their bodies.
但是并不简单，由于这种动物身体缺乏硬质部分。

461
00:38:25,480 --> 00:38:29,480
If I was working on dinosaurs,
I'd go to a spot,
如果我是研究恐龙的，我会找到采掘点位，

462
00:38:29,480 --> 00:38:34,760
find the bones and carefully dig them up, 
take them back into the lab,reconstruct the dinosaur.
找到骨头后小心地把它们挖出来，把它们带回实验室，复原出恐龙来。

463
00:38:34,760 --> 00:38:40,640
But I'm not dealing with bones.
I'm dealing with soft-bodied creatures.
但是我不处理骨头。我处理的是软体的动物。

464
00:38:40,640 --> 00:38:46,280
All you've got are imprints of squishy things living flat on the seafloor.
所有你得到的是软体在海平面上留下的压痕。

465
00:38:47,800 --> 00:38:52,160
Despite the challenges, 
Jim has discovered compelling evidence here
尽管面临挑战，Jim已经在这里发现了绝佳的证据

466
00:38:52,160 --> 00:38:55,320
that these animals had begun to move.
证明动物开始运动了。

467
00:38:58,200 --> 00:39:02,280
On this fossil bed, 
we find something very interesting.
在化石层上，我们发现了些非常有趣的东西。

468
00:39:02,280 --> 00:39:06,560
It's a series of faint，but very definite circles.
是一系列模糊，但是显然是个圈。

469
00:39:06,560 --> 00:39:11,160
They are almost identical in size and they overlap quite often.
它们的大小几乎一样并且经常重叠。

470
00:39:11,160 --> 00:39:15,200
And then when you go to the end of the series of discs,
当观察这些盘状的末端,

471
00:39:15,200 --> 00:39:21,560
you find a hollow with the imprint of a very distinct fossil,
你就会找到一个空的具有十分明显的印记化石,

472
00:39:21,560 --> 00:39:23,120
that of Dickinsonia.
那就是Dickinsonia.

473
00:39:25,080 --> 00:39:28,600
Dickinsonia was a cushion-like creature
Dickinsonia是一种像垫子状的动物

474
00:39:28,600 --> 00:39:31,120
that lay flat on the seafloor.
它们平躺在海底.

475
00:39:31,120 --> 00:39:36,000
It ranged from the size of a penny to that of a bath mat.
大小变化由硬币到浴室防滑垫.

476
00:39:39,360 --> 00:39:43,360
These imprints represent something very important.
这是非常重要的印痕.

477
00:39:43,360 --> 00:39:45,080
They are the first evidence
它们是动物在海底爬行

478
00:39:45,080 --> 00:39:48,600
of a kind of mobilityof animals on the seafloor. 
的一种证据。

479
00:39:50,600 --> 00:39:56,600
The first animal movements were undoubtedly slow,
but perhaps even too slow to notice.
毫无疑问早期动物的移动是非常缓慢的，可能几乎无法察觉。

480
00:39:56,600 --> 00:40:00,880
To see them in action,
you have to speed them up.
为了看到它们的动作，必须快进才行。

481
00:40:04,520 --> 00:40:08,200
Dickinsonia crept from one feeding place to the next,
Dickinsonia取食时，从一个地区爬行到另一个地区

482
00:40:08,200 --> 00:40:13,160
absorbing the organic matter beneath it and then moving on once again.
吸取在它之下的食物后再向前移动。

483
00:40:13,160 --> 00:40:19,880
Perhaps it moved with the help of hundreds of tiny tubular feet,
as starfish do today.
可能它的移动是如现在海星几百个管足来实现的。

484
00:40:24,280 --> 00:40:32,280
The excavations at Ediacara reveal that Dickinsonia wasn't the only mobile creature around.
埃迪卡拉的挖掘显示Dickinsonis并不是仅有的可移动的生物。

485
00:40:32,280 --> 00:40:37,560
Animals everywhere were on the move,
actively seeking food.
动物四处奔波为了寻找食物。

486
00:40:37,560 --> 00:40:45,320
This shape here is a resting place of a slug-like animal called Kimberella.
这个形状是蛞蝓状生物Kimberella的静息痕迹。

487
00:40:45,320 --> 00:40:50,560
And these here, marks, are showing how it fed.
这个痕迹显示它是如何取食的。

488
00:40:50,560 --> 00:40:52,160
It had a proboscis, a snout,
它有一个长鼻子，

489
00:40:52,160 --> 00:40:59,440
and it fed by sifting through the mud, 
making these scratch marks.
它以过滤泥中的食物为食，形成了这样的抓痕

490
00:40:59,440 --> 00:41:03,360
But it tells us more than how this animal fed.
但是化石显示的不仅是这种动物怎样取食的。

491
00:41:03,360 --> 00:41:07,680
It also tells us how it moved
because if you look back this way,
它也告诉我们它是怎样移动的，因为如果你看它身后的这些，

492
00:41:07,680 --> 00:41:09,480
this is where is started feeding
这里是它开始取食的地方

493
00:41:09,480 --> 00:41:13,800
and then it moved along here with more feeding marks and grooves,
之后它沿着这里移动到这里 一路上留下了取食痕迹和凹槽

494
00:41:13,800 --> 00:41:16,720
and then it settled down here
之后它静息于这里

495
00:41:16,720 --> 00:41:19,240
into the mud where its final resting place was.
在最后的停留之地休眠

496
00:41:19,240 --> 00:41:23,200
So this shows that the animal not only fed like that,
所以这里不仅显示了这种动物的取食方式，

497
00:41:23,200 --> 00:41:25,440
it actually moved like that.
实际上是像这样移动的。

498
00:41:27,200 --> 00:41:32,400
Kimberella was a very early ancestor of today's molluscs.
Kimberella 是现生软体动物的最早的祖先。

499
00:41:32,400 --> 00:41:34,960
It probably had a single muscular foot,
它很可能有单独的肉足，

500
00:41:34,960 --> 00:41:37,440
just as snails and slugs have today
正如蜗牛与蛞蝓一样

501
00:41:37,440 --> 00:41:41,280
with which it pulled itself along the sea bottom.
这使得它们能够在海底移动。

502
00:41:41,280 --> 00:41:45,000
Our speeded-up view of the Ediacaran seafloor
我们通过Edicaran海底的快进的视角。

503
00:41:45,000 --> 00:41:48,880
gives an idea of what a busy place the oceans had now become.
展现当时的海底热闹情形。

504
00:42:01,040 --> 00:42:05,560
Whether that movement is by creeping or crawling over the seafloor,
至于在海底移动的动物是爬行还是蠕动并不重要。

505
00:42:05,560 --> 00:42:07,840
it doesn't matter because that animal
因为这些动物

506
00:42:07,840 --> 00:42:12,600
has advantages over an animal that is fixed to the seafloor.
对于在海底固定的动物（错点的）来说是先进的。

507
00:42:12,600 --> 00:42:14,720
It can move away from danger.
它能够逃离危险。

508
00:42:14,720 --> 00:42:18,240
It can move towards richer sources of food.
它能够向丰盛的食物资源之地移动。

509
00:42:18,240 --> 00:42:23,760
It can move away from places which are over-colonised by its neighbours.
它能够从过多的邻居之地离开。

510
00:42:23,760 --> 00:42:28,120
That gives it an enormous advantage in the history of life.
因此这是生命史上巨大的进步。

511
00:42:38,000 --> 00:42:45,000
This new mobility was only made possible by a major change in the layout of animals' bodies.
移动能力出现的原因可能是动物身体设计改变。

512
00:42:46,520 --> 00:42:51,640
When we get to Ediacara,
we still have some of those beautiful fractal-like forms
在Ediacara我们仍然找到许多漂亮的分形生物形式

513
00:42:51,640 --> 00:42:59,520
that you see at Mistaken Point but in the Ediacara Hills we see something very different
你在错点看到的

514
00:42:59,520 --> 00:43:01,480
and that is, for the first time,
不同于Ediacara山上看到的，这就是了。

515
00:43:01,480 --> 00:43:08,360
you see a blueprint for all animals from then on, including ourselves.
你看到了包括我们在内的所有动物的蓝图在那之后形成了。

516
00:43:09,880 --> 00:43:15,680
'The modern animal body plan is called bilateral symmetry.'
现代动物的身体构型被称为两侧对称。

517
00:43:15,680 --> 00:43:17,840
What we see here is Spriggina.
在这里看到的是Spriggina。

518
00:43:21,680 --> 00:43:23,520
Let's make a cast of the fossil.
让我们看看这种生物的大致形态。

519
00:43:25,120 --> 00:43:30,280
Spriggina represents the first ever animal
Spriggina代表了最早具有明显的

520
00:43:30,280 --> 00:43:33,800
which hadclear bilateral symmetry.
两侧对称特征的动物。

521
00:43:33,800 --> 00:43:38,280
It had a body with a head at one end, a tail at the other.
它有一个有头有尾的身体。

522
00:43:38,280 --> 00:43:42,480
And almost identical halves,
if you split it down the middle.
如果你沿着中间切开，会分为同样的两半。

523
00:43:45,400 --> 00:43:48,760
We see these together with other creatures
我们看见这些和其他具有这类

524
00:43:48,760 --> 00:43:52,360
which have this kind of body form.
身体结构的生物。

525
00:43:52,360 --> 00:43:56,560
Spriggina is just one of countless kinds of fossils
Spriggina是无数种类中的一个

526
00:43:56,560 --> 00:44:00,160
in the Ediacara Hills that had developed in this way.
以这样的方式演化的在Ediacara山上的生物。

527
00:44:01,680 --> 00:44:07,080
It had a head and a tail, and so it moved in a particular direction.
它是具有头和尾的，因此可以朝一个方向移动。

528
00:44:10,800 --> 00:44:16,200
It's quite likely that they had sensory organs concentrated in the head.
很可能它们的头部具有感官。

529
00:44:16,200 --> 00:44:20,480
Now why does my nose occur near my mouth?
为什么我的鼻子靠近我的嘴巴呢？

530
00:44:20,480 --> 00:44:24,600
It's a very good reason. 
I want to smell the food before I ingest it.
这有一个很好的理由。在我吃到食物之前我要先闻到它。

531
00:44:24,600 --> 00:44:27,520
Why are my eyes above my mouth?
为什么我的眼睛在我的嘴上面呢？

532
00:44:27,520 --> 00:44:29,280
So I can see what I'm eating.
这样我才能看到我吃的是什么？

533
00:44:29,280 --> 00:44:36,520
This head demonstrates that sensory capacity had evolved.
头部证明了感官能力的发展。

534
00:44:36,520 --> 00:44:41,560
It was able to sense where food was likely to be on the seafloor.
能够在海底感觉到哪里有食物。

535
00:44:41,560 --> 00:44:47,280
And，therefore，clearly had a mechanism for actually moving towards that food.
具有这样的机制，取食变得更加有效了。

536
00:44:49,360 --> 00:44:54,640
Bilateral animals like Spriggina had another advantage.
两侧对称动物像Spriggina有另一个好处。

537
00:44:54,640 --> 00:44:58,680
Between the head and the tail,
there are numerous segments.
在头尾之间，有很多体节。

538
00:45:00,800 --> 00:45:06,760
So these animals could increase in size by simply adding more segments.
因此这种动物只要增加更多的体节就可以使自己变得更大。

539
00:45:06,760 --> 00:45:11,760
What is more, each segment could do a particular job.
此外，每一个体节有不同的分工。

540
00:45:11,760 --> 00:45:13,040
Once you start to move,
一旦你要开始移动，

541
00:45:13,040 --> 00:45:16,040
you develop a front end and that becomes your head.
开发的前端变成了你的头部。

542
00:45:16,040 --> 00:45:19,160
And you also, by definition，have a back end.
当然因此，也有了后端。

543
00:45:19,160 --> 00:45:23,120
And in between, segments on which you can add appendages.
在它们之间，每一个体节上可以加上具有附肢。

544
00:45:23,120 --> 00:45:26,680
On that basic pattern,
you can add further features.
在这种构型的基础上，你可以加以不同的形态。

545
00:45:26,680 --> 00:45:30,960
On the front end, that's where you need sense organs, eyes, feelers. 
在前端，你需要感觉器官，如，眼睛，触角。

546
00:45:30,960 --> 00:45:34,200
On the appendages, you can modify them to be hooks and claws
在附肢上，你可以改动为勾或爪

547
00:45:34,200 --> 00:45:36,120
that would help you to catch things.
帮助抓握的结构。

548
00:45:36,120 --> 00:45:42,400
And at the back end, there will be a pore from which you excrete the waste products.
在末端，具有排泻废物的孔。

549
00:45:42,400 --> 00:45:48,440
And that is the basic body plan of almost all the animals that are alive on Earth today.
那是现生的大部分动物基本的身体构型。

550
00:45:50,760 --> 00:45:57,360
It had taken 3,000 million years for multi-celled organisms to appear for the first time.
30亿年的时间多细胞生物首次出现在地球上。

551
00:45:57,360 --> 00:46:03,240
But now, less than 100 million years later, 
an evolutionary blink of an eye,
但是现在，不到1亿年的时间眼睛就演化出来了，

552
00:46:03,240 --> 00:46:09,840
animals had appeared that had the same basic body plan as most that live today.
动物自出现开始就与大多数现生的具有同样的身体构型。

553
00:46:09,840 --> 00:46:13,040
They had heads and tails and segmented bodies.
它们具有头部和尾部，有体节的身体。

554
00:46:13,040 --> 00:46:16,000
And they were able to move to find food.
能够移动觅食。

555
00:46:17,520 --> 00:46:21,640
How was it that animals had suddenly become so complex?
这些动物是如何突然变得复杂的？

556
00:46:24,040 --> 00:46:29,600
The Ediacara Hills may hold the evidence for an answer to that question.
Ediacara山可能具有这些问题的答案了。

557
00:46:34,480 --> 00:46:38,080
Living organisms don't live forever.
活着的生物并不永远活着。

558
00:46:38,080 --> 00:46:46,120
If a species is to survive
it has to reproduce and the first simple animals did that very simply,
如果一种生物想要存活必须要繁殖下去 

559
00:46:46,120 --> 00:46:48,480
by straightforwardly dividing.
对于最初简单的动物而言最简单的就是直接分裂

560
00:46:48,480 --> 00:46:56,240
But if a species is to survive
it also has to have the ability to change with a changing environment.
但是一种生物想要存活下去必须要有随着改变着的环境而改变的能力。

561
00:46:56,240 --> 00:47:01,920
And to do that involves reproducing in a rather different way.
这就需要以截然不同的方式繁殖。

562
00:47:01,920 --> 00:47:09,040
Evidence of how that happened can also be seen is these very ancient Australian rocks.
在古老的澳大利亚岩石中能发它们繁殖方式的证据

563
00:47:20,640 --> 00:47:25,640
In 2007, palaeontologist Dr Mary Droser
在2007年，古生物学家 Mary Dorser博士

564
00:47:25,640 --> 00:47:30,040
discovered in these 550-million-year-old deposits
发现在这些5.5亿年前的古老沉积岩

565
00:47:30,040 --> 00:47:34,360
evidence that animals had started to reproduce sexually.
有动物出现了有性生殖的证据。

566
00:47:36,960 --> 00:47:41,320
The animal concerned is called Funisia.
这类动物被称为Funisia。

567
00:47:44,320 --> 00:47:48,880
If Droser's theory is right,
this wormlike creature 
如果Droser的理论是对的，这种蠕虫状的动物

568
00:47:48,880 --> 00:47:53,440
produced off spring by exchanging genetic materialwith other individuals.
能通过彼此交换遗传物质生育后代。

569
00:47:53,440 --> 00:47:56,560
This gene-swapping, or sex,
这种基因重组或者说有性生殖。

570
00:47:56,560 --> 00:48:02,680
shuffles the genetic pack,
greatly accelerating variation and therefore evolution.
变化大大加快了，因此有了演化。

571
00:48:07,280 --> 00:48:10,800
Sexual reproduction is absolutely one of the most fundamental steps
有性生殖绝对是最基础的步骤

572
00:48:10,800 --> 00:48:12,120
in the history of life.
在生命演化史中。

573
00:48:12,120 --> 00:48:14,600
It is why we have the diversity that we have.
这就是为什么我们有今天看到的多样性。

574
00:48:14,600 --> 00:48:16,240
It's the birds and the bees.
比如说鸟类和蜜蜂。

575
00:48:16,240 --> 00:48:20,680
As far as we know, this is the first evidence of animals' sexual reproduction,
据我们所知，这是动物有性繁殖最早的证据。

576
00:48:20,680 --> 00:48:24,320
and we're not catching the animal in the act of it,
虽然我们没有找到这种动物行为的例子。

577
00:48:24,320 --> 00:48:29,520
we're looking at the product of what we conclude was sexual reproduction.
但我们寻找被推断为有性繁殖的产物。

578
00:48:29,520 --> 00:48:33,240
This fossil is key to Mary Droser's argument.
这些化石是Mary Droser博士讨论的关键。

579
00:48:33,240 --> 00:48:37,240
The small circles show where the animals were anchored to the ground.
圆圈状物是用来让这些动物锚定在地面上的。

580
00:48:38,760 --> 00:48:43,440
You can see that these attachment structures are basically all the same size.
你能看见它们附属物的结构都是同样大小。

581
00:48:43,440 --> 00:48:46,720
They're all about a couple of millimetres in diameter.
它们的直径大约都是几个毫米。

582
00:48:46,720 --> 00:48:51,160
And you could go to another bed，and all the Funisia are half a centimetre in diameter.
你去另外一个点去观察那里的Funisia的直径大约一厘米长。

583
00:48:51,160 --> 00:48:54,360
So the same size are all occurring together.
因此同时出现同样的大小。

584
00:48:54,360 --> 00:48:59,960
This uniformity of size in a particular place is,
Mary Droser believes,
不同地点大小的一致性

585
00:48:59,960 --> 00:49:04,560
strong evidence that a new way of reproducing had arrived.
Mary Droser博士认为这是新繁殖方式的有力证据。

586
00:49:04,560 --> 00:49:06,760
We link this to sexual reproduction
我们把这种情况联系到有性繁殖

587
00:49:06,760 --> 00:49:11,120
because if you look in modern environments, 
when you have this kind of size groupings,
因为如果你观察现代环境中的这种大小分组的情况

588
00:49:11,120 --> 00:49:16,880
that is 99.9% of the time a product of sexual reproduction.
99.9%是有性生殖的产物。

589
00:49:18,240 --> 00:49:25,000
To understand why, I'm travelling 2,000 miles northeast of Ediacara to the Great Barrier Reef.
为了找到原因，我从Ediacara北部旅行到2000英里的大堡礁。

590
00:49:29,120 --> 00:49:35,880
Here, there are modern creatures that reproduce in the way that Funisia is thought to have done.
这里是Funisia繁殖方式的现代实例。

591
00:49:35,880 --> 00:49:38,120
They're corals.
它们是珊瑚。

592
00:49:46,960 --> 00:49:51,600
Corals，like Funisia，are anchored to the seabed.
珊瑚与Funisia很相似都锚定在海底。

593
00:49:51,600 --> 00:49:56,200
They feed by filtering food from the water.
它们以过滤水中的食物为食。

594
00:49:58,760 --> 00:50:04,400
And the way they breed creates one of nature's greatest annual spectacles.
它们繁殖的方式是自然界中的奇观之一。

595
00:50:06,800 --> 00:50:11,720
Once a year, there's an important event among the corals.
每年，对于珊瑚来说是最重要的事情。

596
00:50:11,720 --> 00:50:13,800
We're not sure how it's coordinated.
我们不清楚它们之间是怎样协调的。

597
00:50:13,800 --> 00:50:16,360
It probably has something to do with the moon.
很可能是由于月球的作用。

598
00:50:16,360 --> 00:50:22,240
But it gives us a hint as to how sexual reproduction might have first appeared.
但是它们启示了我们有性繁殖如何出现的。

599
00:50:30,080 --> 00:50:33,280
At exactly the same time,
是在完全相同的时间里，

600
00:50:33,280 --> 00:50:38,920
the corals release countless millions of sperm and eggs all at once.
全部的珊瑚一次性释放出无数的精子和卵子。

601
00:50:48,760 --> 00:50:52,760
The event is precisely timed to maximise the chances
这样使得受精的机率

602
00:50:52,760 --> 00:50:54,520
of fertilisation.
实现了最大化。

603
00:50:56,040 --> 00:50:59,840
Millions of offspring are simultaneously conceived.
数百万的后代同时孕育而生。

604
00:51:05,480 --> 00:51:09,680
So，as the coral grows，the individuals that make up
因此当珊瑚虫生长时，

605
00:51:09,680 --> 00:51:15,160
the colonies are all of exactly the same age and size,
群体中的每个个体都有完全相同的年龄和大小，

606
00:51:15,160 --> 00:51:17,360
just like Funisia.
正如Funisia一样。

607
00:51:22,040 --> 00:51:26,520
It's unlikely that Funisia was the first animal to reproduce sexually.
Funisia不像是最早具有有性生殖的动物。

608
00:51:26,520 --> 00:51:33,640
But its discovery suggests that many other animals are also reproducing by mixing their genes.
但是研究表明许多动物也有混合遗传基因的繁殖方式。

609
00:51:33,640 --> 00:51:39,440
And that might explain how complex animals evolved so quickly.
这可以解释复杂的动物何以演化的如此迅速。

610
00:51:44,120 --> 00:51:48,600 
The arrival of sexual reproduction speeded evolution.
有性繁殖的出现加速了演化。

611
00:51:48,600 --> 00:51:53,520
Here was a mechanism that produced greater genetic variation more quickly.
这是更快速地产生更大遗传变异的机制。

612
00:51:53,520 --> 00:51:59,560
So，over many generations，species were able to adapt to their changing environments.
因此经过很多世代后，物种能够适应环境的改变。

613
00:52:01,080 --> 00:52:07,600
550 million years ago，animal life was on the verge of a major advance.
5.5亿年前动物在里程碑级事件的边缘。

614
00:52:09,160 --> 00:52:15,720
In an environment where animals were becoming more mobile，
they would have to adapt fast.
在环境中动物变得更具移动性，可以迅速适应环境。

615
00:52:15,720 --> 00:52:19,320
Movement requires a lot of energy.
移动需要很多能量。

616
00:52:19,320 --> 00:52:22,600
Simply absorbing nutrients through the surface of the body
像Dickinsomia一样简单地通过身体在环境中吸收营养物质

617
00:52:22,600 --> 00:52:26,120
as Dickinsonia did was much too slow a process.
是过于缓慢的过程。

618
00:52:28,200 --> 00:52:32,360
Mobile animals would need to consume huge quantities of food.
能移动的动物需要消耗大量的食物。

619
00:52:32,360 --> 00:52:37,000
And they would do that by evolving the very first stomachs，mouths and teeth。
它们需要演化出最初的胃、口、牙齿。

620
00:52:39,960 --> 00:52:44,120
You can see how they might have done so in Switzerland...
你可以在瑞士看到它们是怎样做到的...

621
00:52:48,040 --> 00:52:53,360
where a new kind of technology provides a window into the past.
新的技术为过去打开了新窗口。

622
00:53:00,600 --> 00:53:06,400
This stadium-sized building houses one of the world's most powerful microscopes.
这个体育场般大小的建筑是世界最大的显微镜之一。

623
00:53:11,440 --> 00:53:14,480
It's called the synchrotron.
被称为同步（辐射）加速器。

624
00:53:19,360 --> 00:53:25,080
Professor Philip Donoghue is preparing the tiniest of fossils for the synchrotron.
Philip Donoghue教授是用同步加速器观察最微小的化石的。

625
00:53:27,400 --> 00:53:33,080
These miniscule balls were excavated from a quarry in South China.
这些小球粒是采自中国南部的采石场。

626
00:53:33,080 --> 00:53:38,680
Each and every one of them is the fossilised embryo of an ancient creature.
它们中的每一个都是古代动物的胚胎化石。

627
00:53:42,840 --> 00:53:45,400
If we really want to understand these fossils,
如果我们真的想了解这些化石

628
00:53:45,400 --> 00:53:48,080
what we need to do is not just to look at the surface
我们要做的不仅仅观察它们的表面

629
00:53:48,080 --> 00:53:50,360
which we can do with an electron microscope.
因此要用到电子显微镜。
630
00:53:50,360 --> 00:53:51,520
We need to look inside.
我们需要观察它们的内部。

631
00:53:51,520 --> 00:53:56,720
We have to use some form of X-ray tomography，
a bit like CAT scanners in hospitals.
我们得用X断层摄影术，类似于医院用的CAT扫描仪。

632
00:53:56,720 --> 00:54:03,160
But we have to use one that allows us to look at the very tiniest details down to a thousandth of a millimetre.
并且我们得观察到千分之一毫米的细节。

633
00:54:03,160 --> 00:54:06,280
The synchrotron is the only
X-ray type machine that provides
同步加速器是的X射线型仪器

634
00:54:06,280 --> 00:54:11,760
the kinds of resolution that we need to see all the tiny details within the fossilised embryos.
能够让我们观察到胚胎化石的所有细节。

635
00:54:13,280 --> 00:54:15,800
KLAXON SOUNDS
报警声

636
00:54:17,200 --> 00:54:21,640
It was astonishing, I mean it was a real eureka moment
太惊奇了！我是说在那个瞬间做到了

637
00:54:21,640 --> 00:54:26,040
that you could get to the very finest levels of fossilisation,
能够以最好的水平观察到化石化的情况，

638
00:54:26,040 --> 00:54:30,280
the very finest detail that the fossil record could ever give up using this technology.
这种技术显示了最好的细节。

639
00:54:38,920 --> 00:54:46,320
Powerful generators fire high-energy electrons around a circular tube at close to the speed of light.
强大的发电机激发高能的电子在圆形管状轨道内以接近光速运转。

640
00:54:50,200 --> 00:54:58,040
After one million orbits，the electrons emit X-rays so powerful，
在轨道中绕过百万圈后，电子发出巨大能量的X射线，

641
00:54:58,040 --> 00:55:00,240
they can penetrate solid rock or these tiny fossils.
射线可以穿透岩石或是这些化石。

642
00:55:02,160 --> 00:55:05,160
Donoghue uses data from the synchrotron
Donoghue用同步加速器中得来的数据

643
00:55:05,160 --> 00:55:08,600
to build a three-dimensional picture of the fossils.
建立化石的三维图片。

644
00:55:10,120 --> 00:55:15,600
We know it's a fossil embryo because it's surrounded by a preserved egg sac.
我们知道它们是胚胎化石是因为它们被卵囊包裹着。

645
00:55:15,600 --> 00:55:20,200
And using tomography we can see inside to the developing animal.
并且用X射线断层照相术我们能够观察到胚胎发育的内部情况。

646
00:55:25,480 --> 00:55:30,520
This fossil is the embryo of a tiny marine worm called Markuelia.
这个化石是被称为Markuelia的小型的海生蠕虫。

647
00:55:32,040 --> 00:55:36,680
It lived just twenty million years after the animals of Ediacara.
它生活在Ediacara动物群灭绝后的2千万年。

648
00:55:43,440 --> 00:55:48,360
Using his 3D model，Donoghue is able to see inside it
应用3D建模Donoghue

649
00:55:48,360 --> 00:55:51,880
and there he found evidence of something new.
能够通过它们的内部结构找到些新的证据。

650
00:55:53,760 --> 00:55:58,160
These fossils provide the first clear evidence for a gut within animals.
这些化石提供了最早具有消化道的动物的证据。

651
00:55:58,160 --> 00:56:03,360
We can clearly see that there's a mouth right at one end
我们可以看到它的一端有口

652
00:56:03,360 --> 00:56:06,280
surrounded by rings of teeth that extend inside the mouth.
被一圈牙齿围绕并且牙齿延伸到口腔内部。

653
00:56:06,280 --> 00:56:10,840
And then there's a gut that extends all the way through to an anus at the other end.
肠道延伸到另一端的肛门。

654
00:56:12,360 --> 00:56:20,000
Internal digestion enabled Markuelia to extract energy 
from its food in a very efficient way.
Markuelia的内部消化系统使得它能够更有效地从食物中得到能量。

655
00:56:23,280 --> 00:56:29,120
And the fact that it had teeth suggests that it had a new diet -
并且具有牙齿的事实

656
00:56:29,120 --> 00:56:30,960
other animals.
反应了它与其他动物非常不同的食性。

657
00:56:33,400 --> 00:56:38,240
The fact that it's got rings of teeth arranged by its mouth，that it would have averted out
事实上，具有一圈排列在口中的牙齿

658
00:56:38,240 --> 00:56:43,080
or it would have ejected out of its mouth to grasp prey items，
tells us that this thing was a predator.
能够从嘴中伸出牙齿咬住猎物，说明它是掠食者。

659
00:56:47,520 --> 00:56:50,840
For the first time, there were hunters in the oceans.
海洋中最初的猎食者

660
00:56:50,840 --> 00:56:55,800
And that had enormous evolutionary implications.
这有很多的演化意义。

661
00:57:04,400 --> 00:57:11,400
There was about to be an explosion of life that would lay the foundations for modern animals.
这样的生命爆发式演化为后来的现生动物打下了基础。

662
00:57:16,720 --> 00:57:19,040
In another wave of evolution,
演化的另一个辐射事件，

663
00:57:19,040 --> 00:57:23,520
the animal basic body plan became more and more elaborate.
动物基本的身体构型变得越来越精细。

664
00:57:23,520 --> 00:57:27,160
Fearsome predators appeared in the seas,
在海洋中出现了可怕的掠食者，

665
00:57:27,160 --> 00:57:33,720
great monsters on the land and animals became masters of the Earth.
在陆地上出现了主宰地球的巨大的动物。

666
00:57:36,280 --> 00:57:42,400
Next time I continue my journey in the Rocky Mountains of Canada,
下一次，我将在加拿大的落基山脉上继续我的旅行，

667
00:57:42,400 --> 00:57:45,160
the deserts of North Africa
以及北非的沙漠，

668
00:57:45,160 --> 00:57:49,880
and the tropical rainforests of Australia.
还有澳大利亚的热带雨林。

669
00:57:49,880 --> 00:57:56,600
I will discover how and why animals evolved skeletons and shells.
我将发现动物是为何及怎样演化骨骼和硬壳。

670
00:57:56,600 --> 00:57:59,920
How they developed true，picture-forming eyes.
它们是怎样演化为具有成像功能的眼睛的。

671
00:58:01,040 --> 00:58:04,280
How others went to extraordinary lengths
它们是怎样变的异常巨大

672
00:58:04,280 --> 00:58:08,120
to protect themselves from attack.
从而保护自己免于攻击的。

673
00:58:08,120 --> 00:58:14,760
And I shall discover the first animals 
that moved out of the sea to conquer the land and the air.
并且，我将探索最先离开海洋征服陆地及天空的动物。