List three important steps in the early development of life on earth?

- the protoplanet's collision with the earth forms the moon. (during the Hadean,   when earth was nothing but a hot ball of stone, life didn't excist yet).
- the first prokaryote life forms due to meteorite rains. Inside of these meteorites   are the elements needed to create this life (Archean).
- Eukaryotes, a more complex form of life, emerges during the Proterozoic due     to the excistens of oxygen in the sky, which is created by bacterias whom are     prokaryotic.