地球的力量 第1集 火山(20)生命的家園

The early Earth is much more volcanic than it istoday

早期地球的火山活動遠遠多于如今

because its core were so much hotter.

這是因為當時地核熱得多

This provided enough carbon dioxide to compensate the weak sun.

這提供了足夠的二氧化碳來補償虛弱的太陽

Volcanoes prevented the young Earth from freezing over,

防止了地球被凍僵

And so early life was able to survive.

因此早期生命才得以幸存

but even this was not the end of what volcanoes have done for life on Earth.

但火山為地球生命做的貢獻還不止這些。

about 600 million years ago, they also helped trigger the greatest evolutionary leap in Earth'shistory.

大約6億年前，火山還觸發(fā)了地球歷史上最偉大的進化飛躍。

Shark bay in west Australia

西澳大利亞鯊魚灣

is home to some of the oldest life forms on Earth.

是地球上某種最古老生命的家園

These strange domes are made of from layer upon layer of bacteria。

這些怪模怪樣的圓石是由一層又一層的細菌構(gòu)成的

they are called stromatolite.

被稱為“疊層石”。

For most of Earth's long history,

在地球漫長歷史的大部分時間里，

this was the most advanced life on the planet.

這就是地球上最高級的生命形式

For around 2 billion years, stromatolite ruled our world, unchallenged.

疊層石統(tǒng)治世界 時間長達大約20億年 沒有受到任何挑戰(zhàn)。

and there was nothing to suggest that this was ever going to change.

而且沒有任何跡象表明 這種狀況會發(fā)生些微改變

but Earth and the stromatolites was to face a catastrophe,

但是地球和疊層石將要面臨一場大難

perhaps the most serious crisis life has ever faced.

或許一場前所未有的最深重危機