You keep positing invalid distinction between biological and otger mechanisms. There is nothing limiting generations to biological mechanisms. Consider von Neumann's universal constructors or, for purely software mechanisms, the agents within Avida.
We do, in fact, now have machines -- in the software sense -- that have all features necessary for Darwinian evolution to operate. We don't yet have that for hardware devices, but we're fairly close, and we certainly don't need to understand intelligence do build such self-replicating hardware/software systems (though the universality of computation suggests we don't need hardware/software systems, since anything they can exhibit, pure software systems can as well.)
The problem isn't that you haven't explained yourself well, it's that your argument rests on a fundamental distinction between natural biological organisms and all other machines which does not exist.
I think you have to address the parent's argument that machines are not "alive", while biological organisms are.
Of course, first we need to define "alive", and then we should ask: can we build something that will be "alive"?
Do you consider the entities in Avida simulation to be alive? How about biological vs computer viruses? Is there a fundamental difference between them?
If we simulate a biological organism on a atomic level, together with its immediate environment, so that it behaves exactly like its real-world counterpart would, do we call it "alive"?
We do, in fact, now have machines -- in the software sense -- that have all features necessary for Darwinian evolution to operate. We don't yet have that for hardware devices, but we're fairly close, and we certainly don't need to understand intelligence do build such self-replicating hardware/software systems (though the universality of computation suggests we don't need hardware/software systems, since anything they can exhibit, pure software systems can as well.)
The problem isn't that you haven't explained yourself well, it's that your argument rests on a fundamental distinction between natural biological organisms and all other machines which does not exist.