A small fish now provides a great example of rapid evolution, thanks to an accidental experiment.
Pollution control turned Seattle's murky Lake Washington into a beautiful clear lake. Good for us, but the lake's threespine stickleback was suddenly visible to hungry trout. They had to do something quickly if they wanted to survive...evolve. And they did.
Threespine sticklebacks in Lake Washington lost their armor, made up of bony plates, when the lake got dirty and the water got cloudy up until about the mid 1900s. Then, an expensive cleanup in the 1960s made the water clear and sticklebacks because trout food again. The response? Sticklebacks regrew their armor of bony plates.
No sign of intelligent design in this case, just genetic changes that confer a survival advantage.