Imagine that you take a journey through time, starting in the age of the dinosaurs. You see plants and animals as they turn into
fossils, observe Charles Darwin take his voyage, and see him develop his theory. You also see signs of change in populations of organisms and their environments and observe the effects of mutations. Now, imagine that you arrive back in the present day, and everyone whom you tell about your adventure does not believe you. What evidence from the present day could you use to prove that you have taken this journey?
You take any of the "signs of change in populations of organisms and their environments". For imagine, Australopithecus (early man) turning to Homo sapiens. In that way they could tell that you took this journey.
