Evolutionists do not really know how tigers got their stripes, and because of this there are two theories, one of which supports the Gradual Change Hypothesis:

Tigers started off as solid colors with no markings or other colors in their fur. Then a few tigers had a few color variations in their fur, which actually helped them survive and reproduce better. In the next generation of these tigers, there were more with markings and the markings were either more, the same, or less distinct as the original tigers. As generations go on, the tigers with the more distinct color markings, stripes, are able to survive better and therefore reproduce better, so they keep creating more and more offspring and generations of offspring with their markings, and eventually, the majority of tigers in the population will be over come with these stripes.

This demonstrates the Gradual Change Hypothesis because the Tigers change happened very slowly over a longer period of time.

Human teeth size has decreased over the years. A study measuring the L1, L2, C, P1, P2, M1, M2, M3 teeth in several populations of humans have been measured over several spans using skeletons. These changes are a result of a change in the buccal-lingual dimensions. The rate of the width and length of the mandible and maxillary teeth in the Late Pleistocene period was very slowly and gradually decreased; however, the maxillary teeth did decrease in size twice as fast a mandibular teeth. The Post-Pleistocene period showed the same as the Late Pleistocene. It was found that this change was not due to dietary change but rather a food-processing change.

This is an example of gradual change because this change in the size of human teeth happened over a span of several hundreds of years. The entirety of this study was done studying fossils and skeletons to be able to track the change in human teeth.