Some 3.8 billion years ago

3.8 billion years ago 

On this hot early Earth , there were no oceans.

All water existed as gas.But 3.8 billion years ago , our planet cooled enought for water to condensate and become liquid.

The very firs primitive ocean covered this young Earth,and turned it into a waterworld.

H20 is an essential ingredient for creating living things.

So will all at Water,life appeared on Earth about 3.7billion years ago.

These earliest forms of life were microscopic organisms.

But it was nearly a billion years after that,that some of these organisms changed the course of the world.