Evidence supporting the theory of plate tectonics includes the fit of continental margins, the distribution of fossils, and geological features such as mountain ranges and ocean ridges. Key observations include the presence of identical rock types and ages on distant continents, as well as the occurrence of similar species in geographically separated regions. Furthermore, seismic activity and the mapping of ocean floor topography provide insights into how tectonic plates interact, supporting the idea that continents are mobile and have shifted over geological time.