It is estimated, that life arose from molecules with the ability to copy themselves (replication). Does evolution start from the very same moment when any molecules obtain this ability? Or are there certain other conditions, like increased susceptibility to chemical damages so that mutations can occur? Do they have to be complex or could simple molecules also replicate and start evolution?
Is it possible, that life arose several times independently, but only one molecule type prevailed (-DNA) and the others became extinct?