The events of life on earth would require first oxygen which I believe first started to form about 2.5 billion years ago and is seen in the red highly oxidized iron ores (hematite) in such places as the Labrador Trough, secondly fresh water would be required to sustain life so precipitation and concentration in aquifers, lakes and rivers and streams would be essential, thirdly a reasonably warm temperature would be required for life to survive especially early fragile life and fourthly, the natural environment and a food supply would be required for life to form and to fluorish.
