Hey there, welcome to Life Noggin! More animal species have gone extinct in the last 500 years than in the last 20 million years combined.
大家好！欢迎来到脑洞大开的生命奇想！过去500年灭绝的动物物种比过去2000万年灭绝的动物物种加起来还要多。
And incredible creatures like lions, whales, tigers OH MY! and elephants that used to roam freely in huge numbers are now approaching extinction.
像狮子、鲸鱼、老虎、大象这些很棒的动物，从前都大量的漫游在地球上，现在竞也濒临灭绝了。
The number of wild lions has dropped 95% since only the 1950s.
仅仅自1950年以来，野生狮子的数量就下降了95%。
With 75% of all species expected to disappear in the next 300 years, scientists believe that we’re experiencing the sixth mass extinction on Earth.
科学家认为所有物种的75%将在未来300年内消失，现在我们正在经历地球上的第六次大灭绝。
And it’s the fastest one ever recorded. Many of the previous extinctions lasted hundreds of thousands and even millions of years.
而且这次大灭绝是最快的一次。之前历史上很多次大灭绝都历经了成千上万年，甚至长达百万年。
But this one seems to be happening in the blink of an eye.
但是这次大灭绝似乎是一瞬间发生的。
While scientists have found this is due to human activities, the causes for the other five mass extinctions aren’t so crystal clear.
而科学家发现这次大灭绝是人类活动导致的，之前的五次大灭绝发生的原因尚不清楚。
The most recent K-T extinction wiped out the dinosaurs 65 million years ago.
最近一次的白垩纪-第三纪灭绝发生在6500万年前，导致了恐龙的灭绝。

And the general consensus is that an asteroid impact in Mexico is what caused it, but many scientists also point to major volcanic eruptions in India as a likely cause.
普遍的共识是发生在墨西哥的一次小行星撞击导致的这次灭绝，但是也有很多科学家认为发生在印度的一次火山喷发是一个可能的原因。
Both of these catastrophes would’ve stirred up so much dust and debris that they’d block out sunlight, which is necessary for all kinds of life.
这两种灾难都会激起大量的尘埃和碎片，以至于挡住各种生命都需要的阳光。
But how did dinosaurs die, while creatures like frogs, alligators, birds, and lizards survived?
但是为什么恐龙灭绝了，而像青蛙、鳄鱼、鸟类和蜥蜴这样的动物都存活下来了呢？
We may never know, but selectiveness is a theme in mass extinctions.
我们或许永远都不会知道，但是自然选择总是大灭绝发生时的主题。
During the Triassic-Jurassic extinction about 200 million years ago, there was a mass die off of marine creatures and amphibians, but interestingly, plants weren’t really affected.
在两亿年前的三叠纪-侏罗纪大灭绝期间，海洋生物和两栖动物大量死亡，但有趣的是，植物并没有真正受到影响。
About three quarters of all living species went extinct during this event.
大约四分之三的生物物种在这次事件中灭绝。
It’s thought that this was caused by a massive influx of carbon dioxide from major volcanic activity that acidified the oceans and raised air temperatures.
据说，这次灭绝是由于火山活动产生的二氧化碳大量涌入空气和海洋，导致海洋酸化和空气温度升高而引起的。
Before that, there was the Permian mass extinction which has ever so pleasantly been nicknamed “The Great Dying”. Which is a fantastic name for an emo band. Just saying!
在此之前，二叠纪大灭绝曾被亲切地称为“大灭绝”。对于情绪摇滚乐队来说，这是一个很棒的名字。说说而已！
This was the worst extinction event, wiping out 95% of all species on Earth, including insects which is very rare.
这是史上最严重的灭绝事件，地球上95%的物种都灭绝了，包括非常罕见的昆虫。
High CO2 levels in the ocean, massive influxes of methane from sea beds and permafrost, and volcanic eruptions are all considered possible causes.
人们认为可能是海洋中二氧化碳含量高、海床和永久冻土层甲烷大量汇集以及火山爆发导致的这次灭绝。
Going back even further, we find the Late Devonian extinction about 360 million years ago.
再往前追溯，就是距今3.6亿年前的泥盆纪晚期大灭绝。
This extinction was especially prolonged, lasting about 20 million years, and about 75% of all species were killed off.
这次灭绝持续时间特别长，持续了大约2000万年，大约有75%的物种灭绝。
Marine life were especially affected due to a lack of oxygen in the oceans, but sharks survived though, so that’s… good I guess.
由于海洋缺氧，海洋生物受到的影响尤为严重，但鲨鱼却存活了下来，所以这应该是件好事。
There are lots of things that could’ve prompted this - from changing sea levels to new plants altering soil environments.
可能是许多因素导致了这次灭绝——从海平面的变化到新植物改变土壤环境。
The very first mass extinction we know of is the Late Ordovician extinction that took place 450 million years ago.
我们所知的第一次大灭绝是发生在距今4.5亿年前的奥陶纪晚期。
Around this time, a huge ice age caused sea levels to drop, ocean currents to reroute, and oxygen levels in the water to drop drastically.
大约在这个时候，一个大型的冰河时代来临，导致海平面下降，洋流改道，水中的氧气含量急剧下降。
At this point, almost all life still lived in the sea and these events caused 85% of all marine plants and animals to go extinct.
此时，几乎所有的生命仍然生活在海洋中，这些事件导致85%的海洋动植物灭绝。
Some creatures like trilobites and brachiopods survived though.
但是三叶虫和腕足类动物等生物却幸存了下来。
But the big question is, will humans die off in this current extinction? The answer really depends on how plants fare in this war.
但最大的问题是，人类会在这次大灭绝中死掉吗? 答案就在于植物在这次战争中会有怎样的遭遇。
They provide us with food and medicine, and absorb an incredible amount of CO2, keeping global warming a bit more at bay.
植物可以为我们提供食物和药品，并吸收大量的二氧化碳，使全球变暖问题得到控制。
But it’s thought that if plants reach major extinction levels, humans could be next.
但是人们认为，如果植物达到大灭绝的程度，那么人类可能是下一个。
So get out there and water those plants like your life depends on it, because it actually does this time.
所以去给那些植物浇水吧，就像是你的生命依赖于它一样，因为这一次确实是这样的。
Do you have a favorite animal that went extinct? Is it the dodo? Because I love the dodo.
你有最喜欢的已经灭绝的动物吗？是渡渡鸟吗？我超爱渡渡鸟的。
Let me know in the comment section below.
在评论区告诉我你的答案吧。
speaking of extinct animals, should humans even try to bring them back? check out this video where we explored just that!
谈到灭绝动物，人类应该努力让它们重返人间吗?来看看这个视频吧，我们在里面讨论这个问题！
And that’s because, in order to bring these animals back, scientists need bits of their genetic material that have been salvaged. And sadly, DNA from dinosaurs hasn’t survived long enough to be used here.
这是因为，为了让这些动物复活，科学家们需要一些可以找到的它们的基因材料。不幸的是，恐龙的DNA并没有存在足够长的时间以供使用。
That's a bummer. I really want to ride a raptor! As always, my name is Blocko, this has been Life Noggin, don't forget to keep on thinking!
真可惜，我挺想骑一个猛兽的！我是宝高，这里是脑洞大开的生命奇想。思考不要停！