我们星球上的生命（2023）

在恐龙时代之前数百万年
Millions of years before the age of dinosaurs...
我们的星球被同样神奇的巨兽统治着
our planet was ruled by equally magnificent beasts.
两个伟大的王朝已经崛起
Two great dynasties had emerged
并在争夺统治权
and were vying for domination.
本集将讲述陆地征服之战
This is the story of the battle to conquer land...
以及它如何彻底改变地球上的一切
...and how it changed everything for life on our planet.
《我们星球上的生命》
双语合并：村儿南
第 3 章：入侵大地
（5亿年前）
在我们星球的大部分历史中
For most of our planet's history,
陆地都不适于生命居住
land has been inhospitable to life.
一片荒芜
A bleak and desolate realm...
更像是月球表面
more like the surface of the moon...
而不像今天的地球
than like Earth today.
很难想象
It's hard to imagine
任何生命 会在如此充满敌意的地方定居
how anything could ever make this hostile place its home.
但是在海浪之下
But from beneath the waves,
生命已在这里繁荣超过10亿年
where life had thrived for more than a billion years,
有一种好奇的生物率先发出挑战
one curious life-form was among the first to rise to the challenge.
地衣看似不起眼
Lichen may not look remarkable,
但它们其实独一无二
but they are in fact completely unique.
这是一种开创性的合作关系
A pioneering partnership.
地衣既不是植物 也不是动物
Neither plant nor animal,
而是真菌和藻类的奇怪组合
lichen are a strange combination of fungi and algae...
只有在一起
that only together
才能克服贫瘠地球的极度险恶
had what it took to overcome the extreme hostility of barren Earth.
但它们不仅具有开创性
But they were more than just pioneering.
还具有开地性
They were groundbreaking.
随着它们的传播
As they spread...
它们的细丝帮助将岩石分解
...their tiny filaments helped to break down rock
产生了史上第一块土壤
and produce the first ever soil...
为植物的到来铺平道路
paving the way for plants to take over.
苔藓这样的微型植物率先出现
Micro plants, like moss, were first to appear.
叶子只有一层细胞
With leaves only one cell thick,
它们无法向上生长
they couldn't grow upwards,
但可以蔓延开来
but could spread out.
它们的繁殖速度比地衣快
Reproducing faster than lichen,
很快就铺满陆地
they soon carpeted the land,
在之后的4000万年 不受滋扰地统治着陆地
which they ruled undisturbed for the next 40 million years.
但是一场绿色革命即将到来
But a green revolution was coming...
将永远改变陆地的样貌
that would change the landscape forever.
其关键是一种新化合物的进化
Key was the evolution of a new compound,
木质素
lignin.
木质素加强了植物的细胞壁
Lignin strengthened the plants' cell walls...
使植物能够生长得比以往任何时候 都更大、更强壮
allowing them to grow bigger and stronger than ever before.
不再局限于覆盖地面
No longer confined to carpeting the land,
植物开始争夺向上的空间
plants began to battle for the real estate above,
以获取阳光
fighting for access to light.
最终有一些植物长得非常高
Eventually, some plants grew so tall,
从周围的世界中高耸出来
they towered above the world around them.
今天的红杉是大自然的摩天大厦
Today's redwoods are nature's skyscrapers.
高度超过100米
Reaching heights of more than a hundred meters,
是史上最高的生物
they are the tallest living things to have ever existed.
但是红杉只是40万植物物种中的一个
But redwoods are just one of more than 400,000 species of plant,
植物 是我们星球上的生命最鲜明的标志
the most visible signs of life on our planet.
在地球遥远的过去
Back in Earth's distant past,
植物的到来
the arrival of plants
为来自海洋的下一批入侵者 创造了新的栖息地
created new habitats for the next invaders from the sea.
（3.45亿年前）
率先踏上陆地的动物是节肢动物
The first animals to ever set foot on land were the arthropods.
它们是三叶虫的亲戚
Relatives of the trilobites,
坚硬的外骨骼在水下是有用的护甲
their hard exoskeletons had served as useful armor underwater.
在陆地上 这护甲支撑着它们
On land, that armor supported them
并防止水分流失
and prevented them from drying out.
它们也可以通过这坚硬的外壳呼吸
They could also breathe through this tough exterior.
当时的氧气水平比今天高60%
And with oxygen levels 60% higher than they are today,
有一些节肢动物长得异常巨大
some grew to be giants.
节胸蜈蚣
Arthropleura,
地球历史上最大的千足虫
the largest millipede to ever walk the Earth.
长度超过2.5米 宽度超过半米
At over two and a half meters long and a half meter wide,
没有天敌
he has no natural enemies...
所以可以把全部精力放在觅偶上
...so can focus all his energy on finding a mate.
但是对节胸蜈蚣来说
But for Arthropleura,
寻找一位完美的伴侣并不简单
the pursuit of the perfect partner is not straightforward.
因为它看不见
For he's virtually blind...
它的世界仅限于它能感知的范围
...and his world extends only as far as he can sense.
蕨类森林广袤无边
The fern forest is vast,
雌性节胸蜈蚣不知在何处
and a female could be anywhere.
但它的搜寻并不是那么毫无希望
But his search isn't as hopeless as it might seem.
准备交♥配♥的雌性会留下气味痕迹
Females ready to mate leave scent trails
供雄性追踪
for males to follow.
这是黑暗中的一线生机
A lifeline in the darkness.
然而感知雌性曾去过哪里
And yet, sensing where she once was
不同于感知雌性现在在哪里
is not the same as sensing where she is.
它施展魅力的机会终于到来
Finally, his chance to charm can begin.
通过自身甲壳间的摩擦 它唱出了独一无二的情歌♥
By rubbing together parts of his shell, he creates his own unique love song.
在陆地上交♥配♥有时是一件尴尬的事
Mating on land can be an awkward affair.
交♥配♥成功需要完美的配合
Success requires the perfect alignment.
所以在这关键的时刻
So it's important at this critical stage
不容踏错半步
not to put a foot wrong.
3.45亿年之后
345 million years later,
在今天的森林中
and in today's forests,
节肢动物的求爱艺术有了长足发展
the arthropod art of seduction has come a long way.
对于一些护甲较少的节肢动物 尤其如此
Especially for some of the less armored members of the group.
与古代节胸蜈蚣不同
Unlike the ancient Arthropleura,
雄性跳蛛视力超常
male jumping spiders have superb vision
而且只有一粒米那么大
and are no larger than a grain of rice.
体型上的不足
But what they lack in stature...
它们在风格上弥补
they make up for in style.
每个物种都有自己独特的舞蹈动作
Each species has its own signature dance move
来吸引雌性的注意
to attract female attention.
孔雀开屏
The peacock.
侧身摇摆
The side shuffle.
迪斯科舞步
The disco dancer.
还有摇动羽毛
And the feather shake.
雄性进化出了 多彩的服装和精美的舞步
While the males evolved colorful costumes and intricate dance moves...
雌性则进化出了挑剔的品味
females developed impeccable taste.
它的侧身摇摆吸引了雌性的注意
His side shuffle has caught her attention.
但它是否有对方所钟情的舞姿呢？
But has he got the moves she's looking for?
只有最好的才行
Only the very best will do.
雌性摇动腹部 表示自己并不满意
Waving her abdomen signals she's not impressed.
它需要小心
He needs to be careful,
因为挑剔的雌性有时会吃掉求爱者
for fussy females sometimes eat their suitors.
尽管如此
Still...
再努力一把也是值得的
...it's worth one more try.
它显然还在自作多情
Clearly, he's not getting the message.
它在爱情方面也许不太幸运
He may be unlucky in love,
但它的节肢动物王朝却运气不错
but his arthropod dynasty has had better luck.
节肢动物 如今已占据所有动物物种的80%以上
They now make up over 80% of all animal species.
节肢动物成功的秘诀
The secret to arthropod success
在于其简单的分节结构
lies in their simple segmented body plan...
这种结构向无数不同方向进化
...which has evolved in countless different directions.
有的在腿上有眼睛
Some have ears in their legs.
有的眼睛长在杆子上
Others, eyes on stalks.
还有后备护甲板
And armor plating for battle.
不断变异
Variation after variation,
节肢动物的进化
arthropods are evolution
放纵不羁
run wild.
包括其中最出色的奔跑者
Including the greatest runner of them all,
虎甲
the tiger beetle.
它的设计经过了数百万年的精心调整
Its design has been fine-tuned over millions of years.
最新版本为速度而生