It is not just experimentation but also prediction that is important. For example the theory of gravity would lead to the prediction that if a lead weight and a feather are dropped in a vacuum both would fall at the same rate. The theory of evolution might for example predict that the a white bear would have survival advantage in a ice climate. Those sorts of prediction are common in evolution. Again if birds evolved from earlier dinosaurs we would expect to find fossils of a species of dinosaur with feathers.