I’d say that fitness in biology is based upon the relative number of offspring that survive. Species and bloodlines that get too inbred can have lots of offspring, but they do not survive. I contend it is still a matter of fitness of the solution to the problem-set.
Additionally, many approaches with GAs use the approach of the fittest “parents” get extra children, while the worst parents get no children. Weight the reproduction of entities to fitness.
But see, here we’re discussing applications of evolution. NOT intelligent design! For evolution can be tested, modified, checked. ID simply can’t. You can’t even have this discussion about ID because it is fundamentally a supernatural basis. It is because it is.
THAT is what makes ID fundamentally not scientific.
However you wish to phrase it, biological fitness is a function that depends on offspring.
many approaches with GAs use the approach of the fittest “parents” get extra children, while the worst parents get no children.
With a moment of reflection, I'm sure you will see that if one were to use the biological notion of fitness here, one would be trying to determine the offspring of a parent in terms of a function that depends on the offspring of the parent. So the program would simply (and obviously) not work.