Based on an apparent fit between Africa and South
America, Wegener hypothesized that at one time all continents were joined together in a "supercontinent" called Pangaea. The supercontinent eventually broke into the smaller continents, which then "drifted" towards their present positions.
Wegener supported his hypothesis by using circumstantial evidence, similar to the way that a detective would collect evidence to solve a crime. There are four lines of evidence: