Let's say that your job is to solve some problem and want to use a genetic algorithm to solve it.

You probably have to build a model, a simplified version of the reality, and find out a fitness function which makes sense in that model, which is fast to calculate etc.

Probably you have to be clever, you have to somehow have an intuition of what matters and what doesn't. That is, you have to know when your cow is too spherical.

This task requires intelligence, and I'm sure that creativity will certainly help making a leap forward, especially if the problem is not well known in advance, or you benefit from solving it in a completely different way.

But, this doesn't mean that each fitness function that will solve the problem, given enough time, will require creativity, or even intelligence!

Natural selection provided really ingenious solutions to a huge set of problems of any kind. The fact that we are discussing this very fact is an astonishing achievement of that very fitness function which is natural selection.

But nobody designed this fitness function, and so long we are interpreting the word "creativity" meaning "created by a mind", no creativity was required to design this "fitness function" or any of the products of that "genetic algorithm".

Of course, one could argue that "creativity" the very act of "creating" things, even without creators, even just emerging properties of a complex system (like natural selection).

Well, redefining creativity that way is certainly not wrong, but I don't think normally people think about creativity in those terms, but as an intrinsic characteristics of minds (and perhaps also human mind only, to most people, but that's another topic)