In 1912, German geophysicist Alfred Wegener proposed that all land on Earth was once part of a hypothetical protocontinent, which he called Pangaea. Wegener hypothesized that the supercontinent, completely surrounded by a world ocean called Panthalassa, began to drift apart approximately 200 million years ago. Evidence supporting Pangaea’s existence includes the presence of identical species on continents that are now far apart, as well as the continuity of what on different continents? Discuss