早期地球的火山活动远远多于如今
because its core were so much hotter.
这是因为当时地核热得多
This provided enough carbon dioxide to compensate the weak sun.
这提供了足够的二氧化碳来补偿虚弱的太阳
Volcanoes prevented the young Earth from freezing over,
防止了地球被冻僵
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.
但火山为地球生命做的贡献还不止这些。
about 600 million years ago, they also helped trigger the greatest evolutionary leap in Earth'shistory.
大约6亿年前，火山还触发了地球历史上最伟大的进化飞跃。
Shark bay in west Australia
西澳大利亚鲨鱼湾
is home to some of the oldest life forms on Earth.
是地球上某种最古老生命的家园
These strange domes are made of from layer upon layer of bacteria。
这些怪模怪样的圆石是由一层又一层的细菌构成的
they are called stromatolite.
被称为“叠层石”。
For most of Earth's long history,
在地球漫长历史的大部分时间里，
this was the most advanced life on the planet.
这就是地球上最高级的生命形式
For around 2 billion years, stromatolite ruled our world, unchallenged.
叠层石统治世界 时间长达大约20亿年 没有受到任何挑战。
and there was nothing to suggest that this was ever going to change.
而且没有任何迹象表明 这种状况会发生些微改变
but Earth and the stromatolites was to face a catastrophe,
但是地球和叠层石将要面临一场大难
perhaps the most serious crisis life has ever faced.
或许一场前所未有的最深重危机
