[Lurking Libertarian]

If evolution has occurred randomly, why in over 3 billion years has life on earth never randomly wandered back over the line between life and no life?

Because evolution is not random. Mutations are random, but natural selection is not random at all.

[beckett]

Your point is more defensible 3 billion years down the road than it would have been over the many millions of years that it would have taken for RNA to get its act together.

Wow --- were we "lucky" or what?