地球的力量 第2集 大氣(18)光合作用

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最重要的是

they're actually the simplest of life forms,

他們實(shí)際上是最簡(jiǎn)單的生命種類

nothing more than bacteria.

不比細(xì)菌的細(xì)胞多

When you get up close you can see

當(dāng)你靠近觀察

that it's only the outer part that's alive.

就只有外面這一部分是活著的

It's a layer of bacteria that secretes a thin film of slime

這一層細(xì)菌分泌一層薄薄的粘液

which builds up layer upon layer.

一層接一層粘合起來

It might not look like it,

它雖然看起來不怎樣

but these are the most successful Life forms on the planet.

不過這些是地球上最成功的生命種類

These stromatolites have been around

疊層石誕生至今

for 3,500 million years.

已經(jīng)三十五億年了

That's three-quarters of the age of the planet.

相當(dāng)于地球四分之三的年紀(jì)

And yet when they first evolved almost three billion years ago,

同時(shí)它們第一次進(jìn)化是在超過三十億年前

these simple life forms began one of the most important transformations

這些簡(jiǎn)單生命類型開始最重要的變形

the planet has ever seen.

地球目睹了這一切

These stromatolites are special

這些疊層石是特別的

because they did something that was quite extraordinary.

因?yàn)樗鼈冏隽朔浅Ｌ貏e的事情

As they took in the sunlight and photosynthesised,

它們吸收陽光和進(jìn)行光合作用

they broke down the chemical bonds in water

分解水的化學(xué)鍵

releasing something that would completely change the planet.

生成一些能徹底改變地球的東西

They released oxygen.

它們生成氧氣