More animal species have gone extinct in the last 500 years than in the last 20 million years combined.

在過去500年中滅絕的物種比過去2000年中的總和還要多。

And incredible creatures like lions, whales, tigers,

一些美妙的動物，像獅子、鯨魚、老虎，

oh my, and elephants that used to roam freely in huge numbers are now approaching extinction.

天哪，還有大象等自由奔放的動物群，現在都已瀕臨絕種。

The number of wild lions has dropped 95% since only the 1950s.

自20世紀50年代以來，野生獅子的數量就下降了95%。

With 75% of all species expected to disappear in the next 300 years.

預計未來300年內，75%的物種將消失，

Scientists believe that we're experiencing the sixth mass extinction on Earth.

科學家認為我們正在經歷地球上的第六次大滅絕。

And it's the fastest one ever recorded.

滅絕速度打破歷史紀錄。

Many of the previous extinctions lasted hundreds of thousands and even millions of years.

之前許多大滅絕皆歷經幾十萬年，甚至幾百萬年。

But this one seems to be happening in the blink of an eye.

但這次似乎是一眨眼的事情。

While scientists have found this is due to human activities,

科學家發現這是人類活動造成的，

the causes for the other five mass extinctions aren't so crystal clear.

但不清楚其他五次大滅絕的原因。

The most recent K-T extinction wiped out the dinosaurs 65 million years ago.

最近一次白堊紀-古近紀滅絕事件消滅了6500萬年前的恐龍。

And the general consensus is that an asteroid impact in Mexico is what caused it,

人們普遍認為那是小行星撞擊墨西哥造成的，

but many scientists also point to major volcanic eruptions in India as a likely cause.

但許多科學家也指出，印度的大型火山爆發可能是原因之一。

Both of these catastrophes would've stirred up so much dust and debris that they'd block out sunlight,

這兩場災難都會造成大量的塵埃和碎片，它們會阻擋陽光，

which is necessary for all kinds of life.

而陽光是所有生命的必需品。

But how did dinosaurs die, while creatures like frogs, alligators, birds, and lizards survived?

為什麼恐龍滅亡，而青蛙、短吻鱷、鳥類、蜥蜴等生物卻活了下來？

We may never know, but selectiveness is a theme in mass extinctions.

我們可能永遠找不到答案，但適者生存是大滅絕的重要課題。

During the Triassic-Jurassic extinction about 200 million years ago,

大約2億年前的三疊紀-侏羅紀滅絕事件中，

there was a mass die off of marine creatures and amphibians, but interestingly, plants weren't really affected.

大量的海洋生物和兩棲類動物滅亡，但有趣的是，植物並未真正受到影響。

About three quarters of all living species went extinct during this event.

大約四分之三的物種在這次事件中滅絕。

It's thought that this was caused by a massive influx of carbon dioxide from major volcanic activity

人們認為這是火山活動產生的二氧化碳大量湧入所造成，

that acidified the oceans and raised air temperatures.

使海洋酸化、空氣溫度升高。

Before that, there was the Permian mass extinction, which has ever so pleasantly been nicknamed "The Great Dying,"

在此之前，還有二疊紀大滅絕，它的綽號是 「偉大的死亡」，

which is a fantastic name for an emo band, I'm just saying!

這個名字很適合硬蕊龐克樂團，我只是隨便說說！

This was the worst extinction event, wiping out 95% of all species on Earth,

這是最嚴重的滅絕事件，消滅了地球上95%的物種，

including insects, which is very rare.

包括昆蟲，這非常罕見。

High CO2 levels in the ocean, massive influxes of methane from sea beds and permafrost,

海洋中二氧化碳含量高、海床和永久凍土中大量湧入的甲烷，

and volcanic eruptions are all considered possible causes.

以及火山爆發都被認為是可能的原因。

Going back even further, we find the Late Devonian extinction about 360 million years ago.

再往前追溯，我們發現泥盆紀後期滅絕事件大約發生在3.6億年前。

This extinction was especially prolonged, lasting about 20 million years,

這次滅絕的時間特別長，大約持續了2000萬年，

and about 75% of all species were killed off.

約有75%的物種死亡。

Marine life were especially affected due to a lack of oxygen in the oceans,

由於海洋中缺氧，海洋生物受到的影響尤其嚴重，

but sharks survived though, so that's good, I guess.

但鯊魚活了下來，我想這應該算是好事吧。

There are lots of things that could've prompted this,

很多事情都可能導致這種結果，

from changing sea levels to new plants altering soil environments.

從海平面發生變化到改變土壤環境的新植物。

The very first mass extinction that we know of is the Late Ordovician extinction that took place 450 million years ago.

據我們所知，第一次大滅絕是奧陶紀大滅絕，發生在4.5億年前。

Around this time, a huge ice age caused sea levels to drop, ocean currents to reroute,

在這個時候，巨大的冰河期導致海平面下降、洋流改道

and oxygen levels in the water to drop drastically.

以及水中氧含量急劇下降。

At this point, almost all life still lived in the sea

這時，幾乎所有的生物仍生活在海洋中，

and these events caused 85% of all marine plants and animals to go extinct.

而上述原因造成85%的海洋動植物滅絕。

Some creatures, like trilobites and brachiopods, survived though.

不過，像三葉蟲和腕足類等生物活了下來。

But the big question is, will humans die off in this current extinction?

但最大的問題是，人類會不會在這次的滅絕事件中死去？

The answer really depends on how plants fare in this war.

答案取決於植物在這場戰爭中的境遇。

They provide us with food and medicine, and absorb an incredible amount of CO2,

它們為我們提供食物和藥物，並吸收大量的二氧化碳，

keeping global warming a bit more at bay.

遏制全球暖化。

But it's thought that if plants reach major extinction levels, humans could be next.

但有人認為，如果發生植物大滅絕，那麼人類可能就是下一個。

So, get out there and water those plants like your life depends on it, because it actually does this time.

所以，快去幫植物澆澆水，把它當成生死存亡的關鍵，因為這次確實如此。

Do you have a favorite animal that went extinct? Is it the dodo? Because I love the dodo.

你最喜歡的動物滅絕了嗎？是不是渡渡鳥？因為我自己很愛渡渡鳥。

Let me know in the comment section below.

請在下面的評論區留言。

Speaking of extinct animals, should humans even try to bring them back?

說到滅絕的動物，人類是否應該嘗試讓它們復活？

Check out this video where we explored just that!

看看接下來這支探討相關主題的影片!