Continental drift is the theory that suggests that Earth's continents were once joined together as a single supercontinent called Pangaea, and have since drifted apart to their current positions. The evidence supporting this theory includes the matching shapes of coastlines on different continents, similarities in rock formations and mountain ranges across continents, the distribution of fossils of similar organisms on separate continents, and the presence of past glacial deposits in areas that are now located closer to the equator. These pieces of evidence support the idea that continents were once connected and have moved over time.