We still are not close to designing any self-replicating machine. That is still pure science fiction.
That Darwinism seems even superficially plausible depends completely on the ability of living things to reproduce themselves without significant degradation.
Reproduction is the most fundamental characteristic of life. We see it happen everywhere, so we may feel there is nothing “unnatural” about it.
“If people design computer viruses, someone will design AI that improves and replicates itself. This will be a new form of life which outperforms humans,” warns Stephen Hawking.
“A profound and deeply touching play about two men who boldly addressed the greatest questions of all time.” New York Times