There are two continents with an ocean between them. Today, the continents have very different plants and animals on them. However, a geologist found fossils of the same type of organism on both continents. Millions of years ago, when this type of organism was alive, we know it lived in only one place. The geologist is using the fossils as evidence to argue that the two continents used to be touching. How could the continents have gotten so far apart, and how long did it take for this to happen?