worldslaziestbusker wrote:Life may still be starting from scratch in the oceans
That might not necessarily be so. The conditions of the Earth are now radically different from what they were when the first self-replicating molecules formed. It may even be that, rather ironically, the current environment is not proper for such molecules to form.
Also, oxygen is poisonous to any form of primitive cellular life with a metabolism so, once again ironically, the oxygen-rich environment of the Earth would most probably stop any kind of complex self-replicating life-forms with a metabolism from forming. (When in the distant past some organisms started consuming carbon dioxide and producing oxygen, probably due to a mutation, and they proliferated so much that they actually started to efficiently pump the Earth with oxygen, it was almost catastrophic. Only those organism that happened to adapt survived. Good thing too, because multicellular life is probably not possible in practice without a metabolism based on consuming oxygen, which is a very potent fuel.)