I believe that the answer to your question can be found in the "Theogony", an ancient Greek peom written by Hesiod.
In this, the universe was said to have originated from a vast void of darkness, Chaos.
Then, Gaia, the Earth, came next -She was Mother of the Titans, and closely associated with the thought of a "mother nature".
The rest of the Titans were born from her, Prometheus (Another Titan) then created the human race out of mud. So, that's a very basic explanation.