我们星球上的生命（2023）

Lacking water, most amphibians struggled.
但并非全部如此
But not all.
有一种两栖动物 进化出了一种革命性的适应性
One evolved a revolutionary adaptation
使其繁荣发展
that enabled it to thrive.
它的卵进化出了一层保护性外壳
Its egg developed a protective shell
将胚胎保护在“私家泳池”之中
that held the embryo in its own private pool of fluid.
幼崽在其中能够安全地发育 而不会干涸
Inside, the young could develop safely without drying out.
由于蛋的进化
The tie to water
与水的联♥系♥终于被断开
was finally broken by the evolution of this amniotic egg.
这些羊膜动物
Known as the amniotes,
能够以两栖动物无法做到的方式
these creatures could colonize the drier land
在干旱的土地上繁衍
in a way that amphibians could not.
从这一共同祖先开始
And from this one common ancestor,
所有哺乳动物、爬行动物、鸟类
all mammals, reptiles, birds,
以及恐龙都将发展而来
and dinosaurs would descend.
（2.52亿年前）
进化出蛋之后6000万年
Sixty million years after the evolution of the amniotic egg,
羊膜动物已遍布盘♥古♥大♥陆♥
amniotes have spread across Pangaea...
形成两个新的王朝
...producing two new dynasties
无尽的竞争也由此开始
and the start of an endless rivalry.
这些沉睡着的身穿护甲的野兽 是一种原始的爬行动物
These sleeping armored beasts are a primitive type of reptile.
盾甲龙是陆地上最大的动物之一
Scutosaurus, among the largest animals on land.
重量超过一吨♥
Weighing over a ton,
它们地球上最早的巨型食草动物
they are the first giant plant-eaters to roam the planet.
蛋能使它们在干旱的环境下兴旺发展
Amniotic eggs allowed them to flourish in the drier conditions
并前往其他动物去不了的地方
and go where others could not.
但是盘♥古♥大♥陆♥并不只属于它们
But Pangaea didn't just belong to them.
另一条血脉出现了
Another new bloodline had emerged.
它们是哺乳动物的祖先
The ancestors of the mammals.
水龙兽虽然无法与盾甲龙相匹敌
While a Lystrosaurus is no match for a Scutosaur...
但它的亲戚可以
...he has cousins here who are.
丽齿兽
A gorgonopsid.
它是哺乳动物更为显赫的前身
A more impressive forerunner to the mammals.
身长超过三米 体重超过300千克
At over three meters long and 300 kilos,
它能与如今的任何大型猫科动物 一较高下
she rivals any big cat alive today.
它有强大的嗅觉
With her powerful sense of smell,
追踪猎物对它来说易如反掌
tracking her prey is easy.
但是击穿对方的重甲
Getting past their heavy armor
就没那么容易了
will be her greatest challenge.
但它有一样秘密武器
But she has a secret weapon.
刀刃一般的牙齿
Saber-like teeth.
即便如此
Even so,
它仍需要悄无声息地靠近
she'll need stealth to get close.
它必须非常谨慎
She must choose her moment...
选好时机
and her target
选好目标
carefully.
慢慢地
Slowly
悄无声息地
and silently...
展开行动
does it.
哺乳动物与爬行动物的竞争
The rivalry between mammals and reptiles
数亿年来 一直是地球生命的特点
has been a feature of life on Earth for hundreds of millions of years.
但它们的早期崛起并不会持续太久
But their early rise was not to last,
因为在盘♥古♥大♥陆♥遥远的北方
because in the far north of Pangaea,
灾难正在发生
something catastrophic was happening.
埋在地球表面之下多年的巨大力量
Lying dormant for years on end, the colossal forces at work beneath Earth's surface
很容易被遗忘
are easily forgotten.
但这地下熔岩世界
But the molten underworld
总在不停搅动
is always stirring,
寻找弱点
always probing for weakness.
在盘♥古♥大♥陆♥的地壳之下
Beneath Pangaea's crust,
一股极热的岩浆
a plume of superheated magma
正朝着地表前进
was working its way to the surface.
二叠纪的喷发一旦开始
Once these Permian eruptions started...
就无法停止
there was no stopping them.
其特点是规模极大
What made them unique was their monumental scale.
是生命见证过的
They were among the largest,
最大、最猛烈的喷发之一
most violent eruptions that life has ever witnessed.
持续肆虐了10万年
And they raged for 100,000 years.
造成的破坏前所未见
The devastation was unprecedented.
一个面♥积♥相当于半个美国的区域
An area half the size of the United States
被熔岩吞噬
lost to lava.
数百万平方公里
Millions of square kilometers,
曾经充满生命
once so full of life,
却被地球自身所毁灭
obliterated by the Earth itself.
而这还只是刚刚开始
And that was just the beginning.
喷发释放出比熔岩更危险的东西
The eruptions released something far more dangerous than lava.
一种有毒的混合气体
A toxic concoction of noxious gases.
当这些气体与水结合时
When these gases combined with water...
威力强大的酸雨倾泻而下
a potent cocktail of acid rain poured down.
水
Water, the giver of life,
生命的赐予者
the giver of life,
如今却成了生命的毁灭者
was now its destroyer.
毒雨毒害大地
The toxic rain poisoned the ground...
灭绝植物
killing off the plants.
没有了根来固定土壤
Without their roots to bind the soil together...
整个生态系统被冲走
entire ecosystems were washed away.
然而空气中 还有一种更具破坏性的东西
And yet, there was something even more destructive in the air.
一位隐形杀手
A silent killer.
二氧化碳
Carbon dioxide.
火山释放出的二氧化碳
The volcanoes released
比我们今天大气中的二氧化碳多六倍
six times more CO2 than is in our atmosphere today...
导致全球气温升高十度
triggering ten degrees of global warming...
各种气候灾难
...and all the climate devastation
随之而来
that comes with it.
温室效应在大自然的力量下肆虐
Hothouse Earth raged as the forces of nature ran wild.
一片混乱 无处可藏
There was nowhere to hide from the chaos.
海洋受到的影响最为严重
And the oceans were worst affected.
随着海洋变暖和酸化
As they warmed and acidified,
氧含量锐减
oxygen levels plummeted...
最早孕育生命的海洋
turning the seas, where life first took hold,
变成了荒芜的坟场
into a desolate graveyard.
这是地球上第三次
This was the planet's third,
也是最具毁灭性的大规模灭绝事件
and most devastating, mass extinction.
90%的物种
Ninety percent of all species
永远消失
lost forever.
进化树的许多分支完全断裂
Entire branches torn off the evolutionary tree.
许多物种灭绝了
But in the loss of many,
但是少数物种幸存下来
endured the few.
它们是一个过去时代的仅存硕果
All that remained of a bygone age.
其生存从未如此重要
Never had their survival been so important.
一切生命的未来
The future of all life
如今都悬于一线
now hung by a thread.