[...] DNA resembles the Harvard architecture. And we've got viruses. Lots and lots of viruses. Retroviruses, even, that write themselves into DNA. But most viruses depend on data and processor to be two different physical entities, and they do just fine.
So, no, the architecture wouldn't have made a difference. We'd just have different problems (side note to SF writers: Von Neumann-architecture genetics might get *interesting*).[...]