I think they are different topics under different environment. Software changes, a lot, over time. You can hardly recognize a software's source code if you don't touch them for a decade. The features changed, new features added, old features deprecated, etc. On the other hand, over the life time of a person, their DNA will not be changed dramatically. What their cells need to do is just an exactly copy of its genes. There won't be a case where one person needs to grow a third arm, while in software world, we constantly change requirements.

Software evolves more like the evolution of a species: Small changes over time to adapt the ever changing environment.