But, it continues, nature in itself is not dialectic. To mention a case, evolution is not a human product. It is a natural product that predates us. To show this, we have to find the dialectical contradictions. Think of formal logic.
Science uses formal logic and the exercise is often fruitful.
However, the aim is not to find and confirm formal logic, but to reflect specific aspects of reality. Even if that's not the purpose, still formal logic gets confirmed when used fruitfully, but that's a byproduct. I would claim that dialectics could do an even better job that formal logic alone, but still its role would be sublated to the goals of science. On the other hand, this whole question may be a semantic misunderstanding. At least in Hegel, IMO, such restriction in the use of the term doesn't seem to be warranted.