TED2008
Peter Ward: A theory of Earth's mass extinctions
Peter Ward——物种大灭绝
Filmed:
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小行星撞击得到了全部关注。但是《美狄亚假说》的作者Peter Ward认为地球上物种大灭绝是由低等细菌引起的。罪魁祸首是一种叫做硫化氢的有毒物质，在医学上，它可能会成为一种有趣的应用。
Peter Ward - Paleontologist
Peter D. Ward studies life on Earth -- where it came from, how it might end, and how utterly rare it might be. Full bio
Peter D. Ward studies life on Earth -- where it came from, how it might end, and how utterly rare it might be. Full bio
Double-click the English transcript below to play the video.
00:18
So, I want to start out with
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好，首先给大家
00:20
this beautiful picture from my childhood.
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展示一幅漂亮图片，它来自于我的童年。
00:22
I love the science fiction movies.
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我特别喜欢这部科幻片。
00:24
Here it is: "This Island Earth."
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就是这个：《飞碟征空》。
00:26
And leave it to Hollywood to get it just right.
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就让好莱坞好好诠释它吧，
00:28
Two-and-a-half years in the making.
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光制作就花了两年半时间。
00:30
(Laughter)
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（笑声）
00:33
I mean, even the creationists give us 6,000,
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我是说，甚至连神创论者都认为地球及万物是6000年前上帝创造出来的，
00:36
but Hollywood goes to the chase.
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好莱坞还紧随其后。
00:38
And in this movie, we see what we think is out there:
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在这部电影中，我们看到了我们认为存在于太空的东西：
00:42
flying saucers and aliens.
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飞碟和外星人。
00:45
Every world has an alien, and every alien world has a flying saucer,
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每个世界都有外星人，每个外星人的世界都有飞碟，
00:48
and they move about with great speed. Aliens.
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他们移动的速度非常快。外星人。
00:53
Well, Don Brownlee, my friend, and I finally got to the point
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嗯，我和我的朋友Don Brownlee最终
00:56
where we got tired of turning on the TV
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还是厌烦了打开了电视机
00:59
and seeing the spaceships and seeing the aliens every night,
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每天晚上看飞船和外星人，
01:02
and tried to write a counter-argument to it,
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还试着写出不同的观点，
01:05
and put out what does it really take for an Earth to be habitable,
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还有地球成为可居住星球的条件，
01:09
for a planet to be an Earth, to have a place
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还有怎么样才能使星球拥有这样一个地方：
01:11
where you could probably get not just life, but complexity,
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在这里，你很可能不仅会获得生命，而且还有各种各样复杂的事情，
01:14
which requires a huge amount of evolution,
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这需要巨大的演变，
01:16
and therefore constancy of conditions.
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还有稳定的外部条件。
01:19
So, in 2000 we wrote "Rare Earth." In 2003, we then asked,
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所以，2000年我们写了《Rare Earth》一书。2003年，我们又提出疑问，
01:22
let's not think about where Earths are in space, but how long has Earth been Earth?
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我们不要去思考地球在宇宙中的位置，而是要想去想想地球成为地球的时间有多久？
01:27
If you go back two billion years,
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若回到20亿年前，
01:29
you're not on an Earth-like planet any more.
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你所在的星球将不再是类地行星。
01:31
What we call an Earth-like planet is actually a very short interval of time.
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我们所说的类地行星其实是一段很短的时间。
01:35
Well, "Rare Earth" actually
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其实《Rare Earth》
01:37
taught me an awful lot about meeting the public.
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在面对公众方面教会了我很多。
01:40
Right after, I got an invitation to go to a science fiction convention,
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在那之后，我收到了科幻大会的邀请，
01:43
and with all great earnestness walked in.
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我怀着极大的热情走进了会场。
01:46
David Brin was going to debate me on this,
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David Brin本打算与我争辩，
01:48
and as I walked in, the crowd of a hundred started booing lustily.
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但我走进会场时，观众们开始发出嘘声。
01:52
I had a girl who came up who said, "My dad says you're the devil."
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有个女孩走过来，对我说：“我爸爸说你是魔鬼。”
01:55
You cannot take people's aliens away from them
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你不能打破别人对于外星人的幻想，
01:59
and expect to be anybody's friends.
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还指望成为他们的朋友。
02:03
Well, the second part of that, soon after --
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然后呢，刚过了一会儿，
02:05
and I was talking to Paul Allen; I saw him in the audience,
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我在和Paul Allen聊天；在观众群众看到了他，
02:08
and I handed him a copy of "Rare Earth."
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然后我递给他一本《Rare Earth》。
02:10
And Jill Tarter was there, and she turned to me,
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Jill Tarter也在那儿，她转过来，
02:14
and she looked at me just like that girl in "The Exorcist."
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看着我，就像《驱魔人》中的那个女孩。
02:17
It was, "It burns! It burns!"
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“着火啦！着火啦！”
02:19
Because SETI doesn't want to hear this.
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因为“搜寻地外文明计划”可不想听到这个。
02:21
SETI wants there to be stuff out there.
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他们希望外星球上有东西可寻。
02:24
I really applaud the SETI efforts, but we have not heard anything yet.
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我确实会为“搜寻地外文明计划”的努力而鼓掌，可还没听到任何动静。
02:27
And I really do think we have to start thinking
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而且我也确实认为我们必须开始思考
02:29
about what's a good planet and what isn't.
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什么是好星球，什么不是。
02:32
Now, I throw this slide up because it indicates to me that,
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现在我给大家展示这个幻灯是因为它告诉我
02:35
even if SETI does hear something, can we figure out what they said?
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即使“搜寻地外文明计划”听到了一些东西，我们听懂他们说的是什么呢？
02:39
Because this was a slide that was passed
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由于这个幻灯片
02:41
between the two major intelligences on Earth -- a Mac to a PC --
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是在地球上两种智慧----Mac（苹果）和PC（微软）----之间进行转换，
02:45
and it can't even get the letters right --
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而它甚至连字母都弄不对——
02:48
(Laughter)
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（笑声）
02:50
-- so how are we going to talk to the aliens?
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——那我们可怎么跟外星人说话呢？
02:52
And if they're 50 light years away, and we call them up,
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而且，如果他们离咱们50光年远，咱们给他们打电话，
02:55
and you blah, blah, blah, blah, blah,
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然后你叭啦叭啦说了一大堆，
02:57
and then 50 years later it comes back and they say, Please repeat?
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50年后收到回复，他们来了一句：“请再说一遍？”
03:00
I mean, there we are.
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终于联系上了，但他们也听不懂我们在说什么。
03:02
Our planet is a good planet because it can keep water.
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我们的星球是个好星球，因为它能储存水。
03:05
Mars is a bad planet, but it's still good enough for us to go there
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火星就不怎么样，但是如果我们能去，
03:09
and to live on its surface if we're protected.
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而且如果能在受保护的情况下住在它表面，那还是很不错的。
03:11
But Venus is a very bad -- the worst -- planet.
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金星是个非常不好----其实是最不好----的星球。
03:14
Even though it's Earth-like, and even though early in its history
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即使它是类地星球，即使在其初期，
03:17
it may very well have harbored Earth-like life,
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它或许也是类地星球上生命居住的美好港湾，
03:20
it soon succumbed to runaway greenhouse --
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但不久它就败给了一发不可收拾的温室效应——
03:23
that's an 800 degrees [Fahrenheit] surface --
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800度的高温的表面——
03:25
because of rampant carbon dioxide.
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起因就是猖獗的二氧化碳。
03:28
Well, we know from astrobiology that we can really now predict
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我们知道，从天体生物学角度来说，现在确实能够预测
03:31
what's going to happen to our particular planet.
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地球将来会发生什么。
03:34
We are right now in the beautiful Oreo
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在第一个糟糕的微生物时代之后，
03:37
of existence -- of at least life on Planet Earth --
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我们现在正处在地球上至少还有生命存在
03:40
following the first horrible microbial age.
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的美丽奥利奥时代。
03:43
In the Cambrian explosion, life emerged from the swamps,
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寒武纪生命大爆发时，海洋中出现生命，
03:46
complexity arose,
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产生极其复杂的食物，
03:48
and from what we can tell, we're halfway through.
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由此推断，我们已经经历了一半。
03:51
We have as much time for animals to exist on this planet
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第二次微生物时代之前，
03:54
as they have been here now,
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动物已经出现，
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till we hit the second microbial age.
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我们有足够的时间让它们在这个星球上生存。
03:58
And that will happen, paradoxically --
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相反，你听到所有关于地球变暖的事情
04:00
everything you hear about global warming --
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都会发生。
04:02
when we hit CO2 down to 10 parts per million,
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二氧化碳含量减少到百万分之十时，
04:05
we are no longer going to have to have plants
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进行光合作用的植物
04:07
that are allowed to have any photosynthesis, and there go animals.
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将不再生存，当然动物也会消失了。
04:11
So, after that we probably have seven billion years.
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所以，在那之后，我们估计还会有70亿年时间。
04:13
The Sun increases in its intensity, in its brightness,
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太阳的强度和亮度都会增强，
04:16
and finally, at about 12 billion years after it first started,
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最终，在120亿年之后，
04:21
the Earth is consumed by a large Sun,
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巨大的太阳将地球消耗殆尽，
04:24
and this is what's left.
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这就是剩下的。
04:27
So, a planet like us is going to have an age and an old age,
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所以，像我们这样的星球会有寿命，而且是很长的寿命，
04:31
and we are in its golden summer age right now.
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我们现在正处于它的黄金阶段。
04:35
But there's two fates to everything, isn't there?
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但凡事都有两面性，对吧？
04:37
Now, a lot of you are going to die of old age,
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现如今，很多人都会年老而死，
04:40
but some of you, horribly enough, are going to die in an accident.
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但糟糕的是，一些人会死于意外。
04:43
And that's the fate of a planet, too.
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一个星球的命运也同样如此。
04:45
Earth, if we're lucky enough -- if it doesn't get hit by a Hale-Bopp,
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在接下来的70亿年里，咱们要是足够幸运，
04:49
or gets blasted by some supernova nearby
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地球如果不被海勒·波普彗星碰撞，
04:53
in the next seven billion years -- we'll find under your feet.
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或不被它附近的某些超新星消灭掉——我们会在你们脚下发现线索。
04:56
But what about accidental death?
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但是意外死亡呢？
04:58
Well, paleontologists for the last 200 years
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在过去的200年里，古生物学家
05:00
have been charting death. It's strange --
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都一直密切观察并记录死亡情况。
05:02
extinction as a concept wasn't even thought about
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直到法国的Baron Cuvier发现第一只乳齿象
05:05
until Baron Cuvier in France found this first mastodon.
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作为概念，灭绝才开始引起人们的思考。
05:08
He couldn't match it up to any bones on the planet,
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他当时没法把乳齿象和地球上任何一种骨头对应起来，
05:10
and he said, Aha! It's extinct.
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然后就说，啊哈，灭绝了！
05:12
And very soon after, the fossil record started yielding
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不久之后，化石的历史记录开始产生
05:15
a very good idea of how many plants and animals there have been
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一个非常好的想法，那就是，自从人类复杂的生命
05:18
since complex life really began to leave
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真正开始在化石历史上留名的时候
05:20
a very interesting fossil record.
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到底存在有多少植物和动物。
05:23
In that complex record of fossils,
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在化石的复杂历史记录中，
05:26
there were times when lots of stuff
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确实有些时候很多东西
05:28
seemed to be dying out very quickly,
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看起来很快要灭绝了，
05:30
and the father/mother geologists
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于是，地质学家之父或之母
05:32
called these "mass extinctions."
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把这种现象叫作“物种大灭绝”。
05:34
All along it was thought to be either an act of God
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一直以来，人们认为这或许是上帝的行为，
05:36
or perhaps long, slow climate change,
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也或者是长期，缓慢的气候变化。
05:38
and that really changed in 1980,
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1980年，在古比奥附近一块露出地面的岩层
05:40
in this rocky outcrop near Gubbio,
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确实发生了改变。
05:43
where Walter Alvarez, trying to figure out
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Walter Alvarez试图在这儿弄清楚
05:46
what was the time difference between these white rocks,
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这些包含着白垩纪时代生物的
05:49
which held creatures of the Cretaceous period,
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白色岩石相差的年代，
05:51
and the pink rocks above, which held Tertiary fossils.
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还有上方包含了第三纪化石的粉红岩石。
05:53
How long did it take to go from one system to the next?
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从一个时期到下一个时期需要多长时间？
05:57
And what they found was something unexpected.
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他们的发现让人出乎意料。
05:59
They found in this gap, in between, a very thin clay layer,
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他们在一层薄薄的粘土层
06:02
and that clay layer -- this very thin red layer here --
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和那层粘土层之间，有一层很薄的红色土层，
06:05
is filled with iridium.
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里面充满了铱。
06:07
And not just iridium; it's filled with glassy spherules,
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不仅是铱，还有玻璃球粒，
06:10
and it's filled with quartz grains
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和石英颗粒。
06:12
that have been subjected to enormous pressure: shock quartz.
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这些石英颗粒受巨大压力的影响：冲击石英。
06:16
Now, in this slide the white is chalk,
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现在，幻灯片里的白色是白垩粉，
06:18
and this chalk was deposited in a warm ocean.
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积存在温暖的海洋中。
06:21
The chalk itself's composed by plankton
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这种白垩粉本身由从海面跌落海底的
06:23
which has fallen down from the sea surface onto the sea floor,
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浮游生物组成。
06:27
so that 90 percent of the sediment here is skeleton of living stuff,
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所以这种沉淀物90%的成分是活物的尸体，
06:30
and then you have that millimeter-thick red layer,
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接着你就看到了毫米厚的红色土层，
06:32
and then you have black rock.
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然后是黑色岩石。
06:34
And the black rock is the sediment on the sea bottom
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没有浮游生物时，海底的沉淀物
06:37
in the absence of plankton.
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便形成了黑色岩石。
06:39
And that's what happens in an asteroid catastrophe,
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这就是小行星灾难时发生的情况，
06:43
because that's what this was, of course. This is the famous K-T.
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当然是因为这就是当时发生的事。这是著名的白垩纪第三纪灭绝事件。
06:46
A 10-kilometer body hit the planet.
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一个直径10公里的物体撞击了星球。
06:48
The effects of it spread this very thin impact layer all over the planet,
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结果是整个星球都蒙上了一层薄薄的土层，
06:52
and we had very quickly the death of the dinosaurs,
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而且不久之后，恐龙，
06:55
the death of these beautiful ammonites,
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菊石类就灭绝了。
06:57
Leconteiceras here, and Celaeceras over here,
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这是Leconteiceras ，还有Celaeceras ，
06:59
and so much else.
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以及其它许多物种。
07:01
I mean, it must be true,
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我意思是，这肯定是真的，
07:03
because we've had two Hollywood blockbusters since that time,
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因为那时候我们就有了两部好莱坞大片，
07:06
and this paradigm, from 1980 to about 2000,
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从1980年到2000年左右，这个例子已经
07:09
totally changed how we geologists thought about catastrophes.
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完全改变了我们地质学家对灾难的看法。
07:14
Prior to that, uniformitarianism was the dominant paradigm:
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在那之前，均变说是主导思想：
07:17
the fact that if anything happens on the planet in the past,
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也就是说，如果星球上以前发生了任何事，
07:20
there are present-day processes that will explain it.
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会有当代的理论来解释。
07:24
But we haven't witnessed a big asteroid impact,
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但我们还没亲眼见过巨大的小行星撞击，
07:27
so this is a type of neo-catastrophism,
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所以这是新灾变的一种类型。
07:29
and it took about 20 years for the scientific establishment
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而科学的论据真正解决问题
07:32
to finally come to grips: yes, we were hit;
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大约要花20年时间：没错，我们被撞了；
07:34
and yes, the effects of that hit caused a major mass extinction.
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没错，撞击导致了物种大灭绝。
07:39
Well, there are five major mass extinctions
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在过去5亿年里，
07:41
over the last 500 million years, called the Big Five.
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一共有五次物大灭绝，我们称作“Big Five”。
07:44
They range from 450 million years ago
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从4.5亿年前，
07:47
to the last, the K-T, number four,
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到上一次白垩纪第三纪灭绝，也就是第四次，
07:49
but the biggest of all was the P, or the Permian extinction,
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但规模最大的一次是二叠纪生物绝灭事件，
07:53
sometimes called the mother of all mass extinctions.
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有时候也被叫作“大规模灭绝之母”。
07:55
And every one of these has been subsequently blamed
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它们其中的每一次都后来都被归结于
07:58
on large-body impact.
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大型小星球撞击。
08:00
But is this true?
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但这对吗？
08:03
The most recent, the Permian, was thought to have been an impact
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最近一次，也就是二叠纪生物灭绝事件被认为是撞击的结果，
08:06
because of this beautiful structure on the right.
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原因就是右图这个美丽的结构。
08:08
This is a Buckminsterfullerene, a carbon-60.
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这是勃克明斯特富勒，一种碳60，
08:11
Because it looks like those terrible geodesic domes
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因为它看起来很像我心爱60年代的
08:14
of my late beloved '60s,
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网格状球顶，
08:16
they're called "buckyballs."
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叫作“巴基球”。
08:18
This evidence was used to suggest
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这些证据表明了
08:20
that at the end of the Permian, 250 million years ago, a comet hit us.
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在2.5亿年前，也就是二叠纪的末期，一颗彗星撞击了我们。
08:24
And when the comet hits, the pressure produces the buckyballs,
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彗星撞击的时候，压力产生了巴基球，
08:27
and it captures bits of the comet.
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巴基球又抓到了彗星的尾巴。
08:29
Helium-3: very rare on the surface of the Earth, very common in space.
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氦-3：地球表面非常稀少，但在太空里却非常常见。
08:34
But is this true?
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那么这又是真的吗？
08:36
In 1990, working on the K-T extinction for 10 years,
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1990年，在研究了白垩纪第三纪灭绝10年之后，
08:40
I moved to South Africa to begin work twice a year
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我搬到了南非，开始在大卡鲁沙漠工作，
08:43
in the great Karoo desert.
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一年两次。
08:45
I was so lucky to watch the change of that South Africa
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一年年过去后，能看到南非
08:48
into the new South Africa as I went year by year.
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变成了一个新的南非，我感到非常幸运。
08:51
And I worked on this Permian extinction,
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当时我在研究二叠纪生物灭绝事件，
08:53
camping by this Boer graveyard for months at a time.
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每次都在波尔的墓地露营好几个月。
08:56
And the fossils are extraordinary.
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那些化石非常棒。
08:59
You know, you're gazing upon your very distant ancestors.
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要知道，你可是正在看着古老的祖先呢。
09:01
These are mammal-like reptiles.
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他们是类似哺乳动物的爬行动物。
09:03
They are culturally invisible. We do not make movies about these.
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从文化角度讲，我们没见过它们。因为没有关于它们的电影。
09:06
This is a Gorgonopsian, or a Gorgon.
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这是Gorgonopsian（兽孔目爬行动物的一种亚目），也叫Gorgon。
09:08
That's an 18-inch long skull of an animal
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这种动物的头骨有18英寸长，
09:12
that was probably seven or eight feet, sprawled like a lizard,
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身高大概有7或8英尺，爬行的样子像蜥蜴，
09:16
probably had a head like a lion.
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可能长了一颗如狮子一般的头。
09:18
This is the top carnivore, the T-Rex of its time.
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这是顶极食肉动物，称得上当年的霸王龙。
09:20
But there's lots of stuff.
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但有太多东西了。
09:22
This is my poor son, Patrick.
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这是我可怜儿子Patrick。
09:24
(Laughter)
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（笑声）
09:25
This is called paleontological child abuse.
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这是古生物学上的虐待儿童。
09:28
Hold still, you're the scale.
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稳住了，你们可是标尺啊。
09:30
(Laughter)
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（笑声）
09:36
There was big stuff back then.
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那时候还有个大家伙。
09:39
Fifty-five species of mammal-like reptiles.
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55个似哺乳类爬行动物种族。
09:42
The age of mammals had well and truly started
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哺乳动物的时代已经真正开始了。
09:45
250 million years ago ...
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2.5亿年前...
09:47
... and then a catastrophe happened.
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...接着，灾难发生了。
09:50
And what happens next is the age of dinosaurs.
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然后恐龙时代到来。
09:52
It was all a mistake; it should have never happened. But it did.
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这完全是一个错误；本来不应该发生的，但却发生了。
09:56
Now, luckily,
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如今，幸运的是，
09:58
this Thrinaxodon, the size of a robin egg here:
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这种蛇颈龙，跟知更鸟蛋一样大：
10:01
this is a skull I've discovered just before taking this picture --
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在拍照之前我才发现这是头骨--
10:04
there's a pen for scale; it's really tiny --
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这是用来测量的钢笔，确实很小——
10:06
this is in the Lower Triassic, after the mass extinction has finished.
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这是早三叠世时期，也就是物种大灭绝之后。
10:10
You can see the eye socket and you can see the little teeth in the front.
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你能看到眼窝和前方的小牙齿。
10:13
If that does not survive, I'm not the thing giving this talk.
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如果那都没法存活的话，我就不可能是今天演讲的这个人了。
10:18
Something else is, because if that doesn't survive, we are not here;
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还有，若它没有生存下来，我们今天就不会在这里了；
10:22
there are no mammals. It's that close; one species ekes through.
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它们不是哺乳动物。就差了一点儿； 一个物种勉强生存了下来。
10:26
Well, can we say anything about the pattern of who survives and who doesn't?
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那么，我们能够说清楚谁能生存而谁不能这种模式吗？
10:29
Here's sort of the end of that 10 years of work.
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这差不多是10年工作的尾声了。
10:31
The ranges of stuff -- the red line is the mass extinction.
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范围是——红色的线就是物种大灭绝。
10:34
But we've got survivors and things that get through,
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不过我们也有躲过灾难的幸存者，
10:36
and it turns out the things that get through preferentially are cold bloods.
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结果是，优先生存下来的是冷血动物。
10:40
Warm-blooded animals take a huge hit at this time.
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恒温动物这次受到了重击。
10:45
The survivors that do get through
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幸存者
10:47
produce this world of crocodile-like creatures.
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为这个世界繁殖了类似鳄鱼的生物。
10:50
There's no dinosaurs yet; just this slow, saurian, scaly, nasty,
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那时还没有恐龙；只有这种缓慢，蜥蜴类，有鳞，恶心，
10:54
swampy place with a couple of tiny mammals hiding in the fringes.
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多沼泽的地方，有几个小型哺乳动物藏在边缘里。
10:59
And there they would hide for 160 million years,
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他们还将再藏1.6亿年，
11:02
until liberated by that K-T asteroid.
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直到被白垩纪第三季小行星解放。
11:05
So, if not impact, what?
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那么，要是没撞击的话，会怎样呢？
11:07
And the what, I think, is that we returned, over and over again,
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我认为，我们会一次又一次地
11:11
to the Pre-Cambrian world, that first microbial age,
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重回前寒武纪时期，也就是第一个微生物时代，
11:14
and the microbes are still out there.
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而微生物也还仍然存在。
11:16
They hate we animals.
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它们痛恨我们这种动物。
11:18
They really want their world back.
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它们很想重回自己的世界。
11:20
And they've tried over and over and over again.
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而且也一次又一次地努力尝试。
11:24
This suggests to me that life causing these mass extinctions
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这让我想到导致物种大灭绝的生命，
11:27
because it did is inherently anti-Gaian.
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因为它确实本来就与盖亚假说不相容。
11:30
This whole Gaia idea, that life makes the world better for itself --
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盖亚的整个假说就是，生命为其本身使世界更美好——
11:35
anybody been on a freeway on a Friday afternoon in Los Angeles
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周五下午在洛杉矶高速公路上开过车的任何人
11:39
believing in the Gaia theory? No.
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都相信盖亚假说吗？不是。
11:41
So, I really suspect there's an alternative,
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所以，我确实怀疑有其它的理论。
11:44
and that life does actually try to do itself in --
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而且生命确实是试图在做自己。
11:46
not consciously, but just because it does.
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虽然并不是无意识地，但确实如此。
11:48
And here's the weapon, it seems, that it did so over the last 500 million years.
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这就是武器，看起来好像在过去5亿年当中它都是这么做的。
11:52
There are microbes which, through their metabolism,
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通过微生物的新陈代谢，它们
11:55
produce hydrogen sulfide,
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会产生氢化硫，
11:57
and they do so in large amounts.
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而且量相当大。
12:00
Hydrogen sulfide is very fatal to we humans.
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硫化氢对我们人类来说非常致命。
12:03
As small as 200 parts per million will kill you.
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百万分之二百这么小的量就能将你杀死。
12:09
You only have to go to the Black Sea and a few other places -- some lakes --
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只需要去黑海和其它少数几个地方，像一些湖泊之类的，
12:13
and get down, and you'll find that the water itself turns purple.
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蹲下来仔细看，你就会发现水本身变成紫色了。
12:17
It turns purple from the presence of numerous microbes
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变成紫色，是因为数不尽的微生物出现，
12:20
which have to have sunlight and have to have hydrogen sulfide,
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它们必须有阳光，而且还得有硫化氢。
12:23
and we can detect their presence today -- we can see them --
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现在我们能检测到它们的存在，也能看得见，
12:27
but we can also detect their presence in the past.
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但是以前也能检测到。
12:29
And the last three years have seen
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过去的三年时间是在
12:31
an enormous breakthrough in a brand-new field.
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新领域的重大突破。
12:34
I am almost extinct --
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我也快灭绝了——
12:36
I'm a paleontologist who collects fossils.
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我是个收集化石的古生物学家。
12:38
But the new wave of paleontologists -- my graduate students --
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但新一波的古生物学家，也就是我们的研究生们，
12:41
collect biomarkers.
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他们收集生物标记。
12:43
They take the sediment itself, they extract the oil from it,
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他们取沉淀物本身，从其中提取油，
12:47
and from that they can produce compounds
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通过油，又能制作混合物，
12:49
which turn out to be very specific to particular microbial groups.
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结果发现这种混合物适于某种特定的微生物种群。
12:53
It's because lipids are so tough, they can get preserved in sediment
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这是因为油脂太粗糙了，它们可以通过沉淀物保存下来，
12:57
and last the hundreds of millions of years necessary,
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然后经过上百亿年，
13:00
and be extracted and tell us who was there.
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被提取出来，还能告诉我们谁曾经在那儿生存过。
13:02
And we know who was there. At the end of the Permian,
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这个我们知道。二叠纪末期时，
13:05
at many of these mass extinction boundaries,
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在很多物种灭绝的边界上，
13:07
this is what we find: isorenieratene. It's very specific.
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我们发现了这个： isorenieratene（编者注：一种类胡罗卜素化合物，只有在生活在缺氧水化变层附近的绿色硫细菌身上才能找到）。这很具体了。
13:11
It can only occur if the surface of the ocean has no oxygen,
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只有在海面上缺氧时才会产生，
13:15
and is totally saturated with hydrogen sulfide --
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还得完全充满了足够的硫化氢——
13:18
enough, for instance, to come out of solution.
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才会从溶液中析出。
13:21
This led Lee Kump, and others from Penn State and my group,
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这使得来自滨州的Lee Kump和我团队的另外一些人
13:25
to propose what I call the Kump Hypothesis:
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提出了我称为“坎普假说”的理论：
13:28
many of the mass extinctions were caused by lowering oxygen,
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很多物种大灭绝都是由于氧气含量的降低，
13:31
by high CO2. And the worst effect of global warming, it turns out:
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以及二氧化碳浓度的增大。全球变暖最严重的影响就是：
13:35
hydrogen sulfide being produced out of the oceans.
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海洋会产生硫化氢。
13:38
Well, what's the source of this?
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那么，根源是什么呢？
13:40
In this particular case, the source over and over has been flood basalts.
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在这种情况下，反复的根源就是洪流玄武岩。
13:44
This is a view of the Earth now, if we extract a lot of it.
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如果我们从地球榨取的太多，这就是它现在的样子。
13:47
And each of these looks like a hydrogen bomb;
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它们每个都看起来好像氢弹；
13:49
actually, the effects are even worse.
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其实，后果会更糟。
13:51
This is when deep-Earth material comes to the surface,
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这是地下深层物质到了表面，
13:54
spreads out over the surface of the planet.
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然后扩散到星球表面。
13:56
Well, it's not the lava that kills anything,
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并不是火山岩杀死了一切，
13:59
it's the carbon dioxide that comes out with it.
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是二氧化碳。
14:01
This isn't Volvos; this is volcanoes.
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这可不是沃尔沃，这是火山。
14:04
But carbon dioxide is carbon dioxide.
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但二氧化碳就是二氧化碳。
14:07
So, these are new data Rob Berner and I -- from Yale -- put together,
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这些数据是来自耶鲁的Rob Berner和我一起得出的，
14:10
and what we try to do now is
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我们现在试着
14:12
track the amount of carbon dioxide in the entire rock record --
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追踪整个岩层的二氧化碳含量。
14:15
and we can do this from a variety of means --
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我们有很多种方法。
14:18
and put all the red lines here,
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在我称之为“温室物种大灭绝”的情况发生时，
14:20
when these -- what I call greenhouse mass extinctions -- took place.
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就会有这些红线了。
14:23
And there's two things that are really evident here to me,
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对我来说，有两件事非常明显，
14:25
is that these extinctions take place when CO2 is going up.
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那就是，二氧化碳上升会导致灭绝。
14:28
But the second thing that's not shown on here:
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第二件事没有在这展示：
14:31
the Earth has never had any ice on it
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二氧化碳含量为百万分之一千时，
14:34
when we've had 1,000 parts per million CO2.
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地球上从来没有冰。
14:38
We are at 380 and climbing.
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现在已经到了百万分之三百八是，还在继续攀升。
14:40
We should be up to a thousand in three centuries at the most,
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我们最多能在300年后保持在百万分之一千，
14:43
but my friend David Battisti in Seattle says he thinks a 100 years.
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但我在西雅图的朋友David Battisti说他认为一百年就差不多了。
14:47
So, there goes the ice caps,
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这就是冰盖，
14:49
and there comes 240 feet of sea level rise.
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这是海平面上升了240英尺。
14:53
I live in a view house now;
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我现在住在一座景观房子里；
14:55
I'm going to have waterfront.
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将来还会有滨水区。
14:57
All right, what's the consequence? The oceans probably turn purple.
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好吧，会有什么后果呢？海洋很可能变成紫色的。
15:01
And we think this is the reason that complexity took so long
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我们还认为这就是为什么地球上产生
15:04
to take place on planet Earth.
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复杂生命的时间如此之久。
15:06
We had these hydrogen sulfide oceans for a very great long period.
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含有硫化氢的海洋已经存在了相当长的时间。
15:09
They stop complex life from existing.
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它们阻止了复杂生命的存在。
15:13
We know hydrogen sulfide is erupting presently a few places on the planet.
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我们知道，最近在地球上少数地方硫化氢开始爆发。
15:18
And I throw this slide in -- this is me, actually, two months ago --
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给大家展示这个幻灯——哦，这是我，两个月前——
15:22
and I throw this slide in because here is my favorite animal, chambered nautilus.
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给大家展示这个幻灯是因为这是我最喜欢的动物，贝类动物鹦鹉螺。
15:26
It's been on this planet since the animals first started -- 500 million years.
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5亿年前，这个星球上刚有动物的时候它就存在了。
15:30
This is a tracking experiment, and any of you scuba divers,
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这是个追踪实验，你们这些潜水员中任何一个
15:33
if you want to get involved in one of the coolest projects ever,
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如果想加入史上最酷工程之一的话，
15:36
this is off the Great Barrier Reef.
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这就是大堡礁。
15:38
And as we speak now,
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正如我们所说，
15:39
these nautilus are tracking out their behaviors to us.
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我们正追踪这些鹦鹉螺的行动。
15:42
But the thing about this is that every once in a while
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但是关键是，每隔一阵儿，
15:46
we divers can run into trouble,
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我们这些潜水者就会碰上麻烦，
15:48
so I'm going to do a little thought experiment here.
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所以我会进行项思维实验。
15:50
This is a Great White Shark that ate some of my traps.
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这是头大白鲨，它中了我的圈套。
15:53
We pulled it up; up it comes. So, it's out there with me at night.
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我们把它拉了上来。所以，它晚上跟我待在一起。
15:56
So, I'm swimming along, and it takes off my leg.
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我游着泳，它能把我腿扯掉。
15:59
I'm 80 miles from shore, what's going to happen to me?
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当时离岸边80英里，我会怎么样呢？
16:02
Well now, I die.
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现在肯定已经死了。
16:04
Five years from now, this is what I hope happens to me:
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5年之内，我希望这能发生在我身上。
16:06
I'm taken back to the boat, I'm given a gas mask:
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我被拖到船上，别人给我戴上了防毒面具：
16:09
80 parts per million hydrogen sulfide.
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因为硫化氢的含量有百万分之八十。
16:12
I'm then thrown in an ice pond, I'm cooled 15 degrees lower
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然后我被扔进冰池里，体温降了15度。
16:16
and I could be taken to a critical care hospital.
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接下来可能会被送到重症监护室。
16:20
And the reason I could do that is because we mammals
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我会这么做的另外一个原因是因为我们哺乳动物
16:22
have gone through a series of these hydrogen sulfide events,
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已经经历了一系列硫化氢事件，
16:25
and our bodies have adapted.
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我们的身体也已经适应了。
16:27
And we can now use this as what I think will be a major medical breakthrough.
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我认为，可以利用这点成为重大的医学突破。
16:31
This is Mark Roth. He was funded by DARPA.
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这是Mark Roth。他受美国国防部高级研究计划局（DARPA）资助,
16:33
Tried to figure out how to save Americans after battlefield injuries.
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试图弄清楚怎么样才能拯救在战场受伤的美国人。
16:37
He bleeds out pigs.
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他拿猪做实验，把它割伤流血。
16:39
He puts in 80 parts per million hydrogen sulfide --
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注入了百万分之八十的硫化氢——
16:42
the same stuff that survived these past mass extinctions --
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这种物质也是从过去物种大灭绝中存活下来的——
16:45
and he turns a mammal into a reptile.
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然后哺乳动物就变成了爬行动物。
16:47
"I believe we are seeing in this response the result of mammals and reptiles
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“我认为，从这个结果中我们看出，哺乳动物和爬行动物
16:51
having undergone a series of exposures to H2S."
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经受了一系列遭遇——与硫化氢接触。”
16:54
I got this email from him two years ago;
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我两年前收到他的邮件；
16:56
he said, "I think I've got an answer to some of your questions."
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他说：“对于你的一些问题，我想我找到了答案。”
16:59
So, he now has taken mice down
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所以，现在他用小鼠做实验，
17:01
for as many as four hours, sometimes six hours,
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时间是4个小时，有时候6小时。
17:05
and these are brand-new data he sent me on the way over here.
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在我来这儿的路上，他把这些全新的数据发给了我。
17:07
On the top, now, that is a temperature record of a mouse who has gone through --
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现在看，顶部的温度是生存下来的老鼠的体温——
17:12
the dotted line, the temperatures.
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就是那条虚线，表示温度。
17:14
So, the temperature starts at 25 centigrade,
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起始温度是25度，
17:16
and down it goes, down it goes.
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然后下降，下降。
17:17
Six hours later, up goes the temperature.
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六小时之后，又上升。
17:19
Now, the same mouse is given 80 parts per million hydrogen sulfide
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现在，还是同样一只老鼠，同样是这个图，给空气中
17:24
in this solid graph,
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注入百万分之八十硫化氢，
17:26
and look what happens to its temperature.
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观察它的体温变化。
17:28
Its temperature drops.
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下降了。
17:30
It goes down to 15 degrees centigrade from 35,
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从35度降到了15度，
17:34
and comes out of this perfectly fine.
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然后又安然无恙了。
17:37
Here is a way we can get people to critical care.
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这种方法，能让人进重症监护室。
17:40
Here's how we can bring people cold enough to last till we get critical care.
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还能让人的体温冷到一定程度，直到被送进重症监护。
17:46
Now, you're all thinking, yeah, what about the brain tissue?
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现在你们都在想，没错，那大脑组织呢？
17:50
And so this is one of the great challenges that is going to happen.
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因此这是即将发生的最巨大挑战之一。
17:53
You're in an accident. You've got two choices:
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你出意外了。有两个选择：
17:55
you're going to die, or you're going to take the hydrogen sulfide
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死掉，否则你就要呼吸硫化氢，
17:58
and, say, 75 percent of you is saved, mentally.
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大概你75%的心智能被救活。
18:01
What are you going to do?
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怎么办呢？
18:03
Do we all have to have a little button saying, Let me die?
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我们是不是都必须有一个小按钮，写着“让我死吧”？
18:06
This is coming towards us,
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这正在发生，
18:08
and I think this is going to be a revolution.
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我认为这将成为一场革命。
18:10
We're going to save lives, but there's going to be a cost to it.
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我们要拯救生命，但要付出代价。
18:13
The new view of mass extinctions is, yes, we were hit,
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对物种大灭绝，从一个新的角度看，是的，我们被撞击了，
18:15
and, yes, we have to think about the long term,
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而且，是的，我们不得不从长远考虑，
18:17
because we will get hit again.
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因为我们会再次被撞击。
18:19
But there's a far worse danger confronting us.
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但是我们将面对一个更糟的情况。
18:21
We can easily go back to the hydrogen sulfide world.
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要回到那个充满硫化氢的世界轻而易举。
18:24
Give us a few millennia --
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再有几千年的时间——
18:26
and we humans should last those few millennia --
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咱们人类应该还能再活几千年吧——
18:28
will it happen again? If we continue, it'll happen again.
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这种事情会发生吗？如果继续下去的话，肯定会。
18:32
How many of us flew here?
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有多少人是坐飞机来的？
18:34
How many of us have gone through
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有多少人仅仅因为
18:36
our entire Kyoto quota
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今年坐飞机的次数
18:39
just for flying this year?
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就通不过京都议定书中的限额？
18:41
How many of you have exceeded it? Yeah, I've certainly exceeded it.
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有多少人超标了？没错，我肯定超了。
18:44
We have a huge problem facing us as a species.
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对人类种族来说，还有一个重大的问题等着我们。
18:47
We have to beat this.
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我们必须将其解决。
18:49
I want to be able to go back to this reef. Thank you.
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我想重回大堡礁。谢谢。
18:53
(Applause)
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（鼓掌）
18:59
Chris Anderson: I've just got one question for you, Peter.
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Chris Anderson：Peter，我有个问题要问你。
19:01
Am I understanding you right, that what you're saying here
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我是不是理解对了，你的意思是说
19:03
is that we have in our own bodies
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在我们自己身体里
19:05
a biochemical response to hydrogen sulfide
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对硫化氢有一种生化反应，
19:09
that in your mind proves that there have been past mass extinctions
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您认为是由于气候变化才导致了
19:12
due to climate change?
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物种大灭绝？
19:14
Peter Ward: Yeah, every single cell in us
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Peter Ward：对，我们的每个细胞
19:16
can produce minute quantities of hydrogen sulfide in great crises.
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都能产生巨大危机中的微量硫化氢。
19:20
This is what Roth has found out.
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这是Roth发现的。
19:21
So, what we're looking at now: does it leave a signal?
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那么，我们现在面对的是：会有信号吗？
19:23
Does it leave a signal in bone or in plant?
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会在骨头或者植物上有信号吗？
19:25
And we go back to the fossil record and we could try to detect
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然后我们又回到化石记录中试图检测
19:28
how many of these have happened in the past.
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在过去发生了多少事情。
19:30
CA: It's simultaneously
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Chris Anderson：这既是
19:32
an incredible medical technique, but also a terrifying ...
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一种不可思议的医疗技术，但也很恐怖......
19:35
PW: Blessing and curse.
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Peter Ward：是把双刃剑。
ABOUT THE SPEAKER
Peter Ward - PaleontologistPeter D. Ward studies life on Earth -- where it came from, how it might end, and how utterly rare it might be.
Why you should listen
Paleontologist and astrobiologist Peter D. Ward studies the Cretaceous-Tertiary extinction event (the one that killed the dinosaurs) and other mass extinctions. He is a leader in the intriguing new field of astrobiology, the study of the origin, distribution and evolution of life in the universe.
In his book Rare Earth he theorizes that complex life itself is so rare, it's quite possible that Earth is the only planet that has any. But, he theorizes, simple life may exist elsewhere -- and possibly be more common than we think.
His upcoming book, The Medea Hypothesis, makes a bold argument that even here on Earth, life has come close to being wiped out several times. Contrary to the "Gaia hypothesis" of a self-balancing, self-perpetuating circle of life, Ward's Medea hypothesis details the scary number of times that life has come close to flatlining, whether due to comet strikes or an overabundance of bacteria.
In March 2009, Ward's 8-hour television series, Animal Armageddon, premieres on Animal Planet Network.
In April 2013, Ward published a surprisingly moving essay about his life's obsession: the chambered nautilus >>
Peter Ward | Speaker | TED.com