[js1138]

If code reuse depended on random chance, nothing would get written.

I think there have been wholly unjustified literal comparisons between DNA and blueprints and DNA and computer programs.

In bacteria, survival is improved by replication errors. The analogy to blueprints is mostly invalid.

[Frumious Bandersnatch]

I think there have been wholly unjustified literal comparisons between DNA and blueprints and DNA and computer programs.

It was your analogy, not mine.

In bacteria, survival is improved by replication errors. The analogy to blueprints is mostly invalid.

Not necessarily.  Firstly, we don't know if these are replication errors, or are a response to environmental stimulii that are within the bacteria's genetic coding.  Secondly, if these are indeed random mutations, they are more likely to cause problems than solve them, so this argues heavily against random chance.  Thirdly, the changes themselves have not been shown to cause a disparate species.