The difference between wild evolution in nature and synthetic evolution in computers is that software has no body. The kind of software you load with floppy disks is straightforward. There is nothing between what the code is and what it does, except the wiring of the machine it runs on.
Biology is vastly different.
If we take a hypothetical hunk of DNA as software code, and alter it, there is a consequential body that must be grown before the effects of the alteration can manifest itself. The same initial alteration of code can have one effect on the growing microscopic fetus and another effect on the sexually mature organism, if it survives that long. This vastly complicates mutational variation. Programming computers is no longer an adequate comparison. You were once the size of a period.