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When you think of mass extinctions you probably think DINOSAURS!
当想到大灭绝的时候，你可能会想到恐龙！
Which I mean, that's fair. Cuz, ya know, dinosaurs.
我的意思是，这很正常。因为，你知道，恐龙。
But the greatest extinction event of all time wasn't the dinosaurs at all.
但是，历史上最大的灭绝事件根本不是恐龙。
About 250 million years ago something caused even more species to die out -- in an event called the end-Permian extinction, also known by its much cheerier name -- the Great Dying.
大约2.5亿年前，有一些东西造成了更多物种的灭绝——这次事件叫做“二叠纪末灭绝”，它有一个更好听的名字——大灭绝。
The Great Dying took out 96 percent of marine species and 70 percent of all land-animals. Yeah.
大灭绝夺去了96%海洋生物和70%陆生动物的生命。是啊。
Scientists have been searching for the exact cause of this mysterious mass extinction for decades, but most scenarios they've come up with have been, well, less than satisfying.
几十年来，科学家们一直在寻找这场神秘大规模灭绝的确切原因，但他们提出的大多数假设都不尽如人意。
However, a researcher at UC Berkeley is on the case, and he might be onto something.
然而，加州大学伯克利分校的一位研究人员正在研究这个问题，他可能会有所发现。
The most convincing theory so far involves the large scale volcanism of the Siberian Traps that happened around the same time as the End-Permian extinction.
到目前为止，最令人信服的理论是西伯利亚陷阱大规模的火山活动，它在与二叠纪末灭绝事件差不多发生在同一时间。
For those playing the home game, that's at the end of the Permian Era.
对于相信这一理论的人来说，这就是二叠纪的终结。
The eruptions exploded 300,000 years before the End-Permian extinction, but were active for hundreds of thousands of years, even after.
在二叠纪末灭绝发生的300,000年前，火山爆发，但它在几十万年，甚至之后，仍然保持着活跃。
They oozed lava and spewed ash all over the place.
他们渗出熔岩，到处喷洒着火山灰。
This would have caused a host of issues like global warming and localized acid rain.
这可能会引发一系列的问题，如全球变暖和局部酸雨。
But how did volcanoes in Siberia manage to wipe out life across the whole planet?
但是西伯利亚火山是如何让整个地球上的生命消失的呢？
To add to the mystery, the end-Permian fossil record shows that a global decline of forests at this time was coupled with mutated pollen.
为了增加神秘感，二叠纪末化石记录表明，此时全球森林面积减少，花粉变异。
Something was making it impossible for plants to reproduce, hmmm.
有些东西造成了植物绝育，嗯。
It's been proposed that the volcanic gases from the Siberian Traps could've severely compromised Earth's ozone layer -- exposing life on earth to extremely high levels of UV-B radiation.
有人提出，西伯利亚陷阱的火山气体可能严重破坏了地球臭氧层——将地球上的生命暴露于极高水平的UV-B辐射中。
Scientists think this could've damaged the plants, potentially destroying the food chain from the bottom up.
科学家们认为这可能破坏了植物，从而破坏了从底部向上的食物链。
This is where UC Berkeley Researcher, Jeffrey Benca, comes in.
这就是加州大学伯克利分校研究员杰夫瑞·本卡的切入点。
To test this theory, he took mini pine trees, and put them in an extinction chamber.
为了证实这个理论，他取了小松树，把它们放在一个消光室里。
Inside they were exposed to extreme amounts of UV-B, akin to what would've been experienced before the Great Dying.
在里面，他们暴露于极高的UV-B辐射中，类似于在大灭绝之前所经历的。
The trees made malformed pollen and became sterile!
树的花粉畸形，变得不育！
What's even crazier though, is four of the five greatest extinctions on earth--- including the dinosaurs-- were accompanied by large scale volcanic events,
甚至更疯狂的是，地球上五大灭绝中的四个——包括恐龙——都伴随着大规模的火山活动，
which are often associated with warming global temperatures, acid rain, and you guessed it: ozone layer depletion.
这些事件通常与全球变暖、酸雨有关，还有你猜到了：臭氧层耗尽。
It's a little too early to say if this new finding helps explain other extinctions.
现在说这个新发现是否有助于解释其他物种灭绝还为时过早。
But it is kinda crazy that Earth's worst extinctions weren't caused by giant asteroids or hellfires, but good old fashioned climate change and ozone depletion, ain't it?
但是，地球上最严重的物种灭绝不是由巨大的小行星或地狱之火引起，而是气候变化和臭氧层消耗，这有点疯狂，不是吗？
If we keep at it, we might just bump The Great dying out of first place.
如果我们坚持这一看法，我们可能会找到大灭绝的原因。
Do you think we could get a trophy for that?
你认为我们能因此获得奖杯吗？
If you're still worried about the ozone layer, you might want to watch this video about how scientists stood up to power and saved it.
如果你仍然忧心于臭氧层，你可能想看看这段视频，看看科学家是如何拯救臭氧层的。
BTW while researching this we found: those volcanic eruptions from Siberia?
顺便说一下，进行此项研究时，我们发现：那些火山爆发来自西伯利亚？
They oozed enough material to cover a region the size of the United States in magma -- a KILOMETER DEEP. Cool. Thanks for watching.
它们渗出了那么多熔岩，足以覆盖一个面积相当于美国的地区——而且足有一公里深。酷。谢谢收看。
