http://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System.
Either something was somehow alive throughout the whole process, or, what I think is more reasonable, life started some time after the formation of Earth.
(italics, my emphasis.)
In my thread “Biologists Replicate Key Evolutionary Step”, you’ll find many current discoveries that allude to this in their consideration. While I have a passive interest in the developments, I’ve not tried to put them together as Newton did his observations of the movements of the heavens in conjunction with the tides and other phenomenon relating to the development of the concept we today hold as “gravity.” Neither am I adverse to life being present as a permanent aspect of existence either. As a student of Objectivism, learning to expand my grasp of both evidence (of the senses) and proof (derived from the evidence of the senses,) are often challenged by integrating the observations in a manner consistent with the method of logic.
The paragraphs cited are what I consider to be the most relevant aspects of the articles linked to. While I don’t aspire to answer this personally, the relevant factors seemed worth identifying at the time.