Continental drift refers to the movement of the continents over the surface of the globe through geological time. As the animation shows, the positions of the main continents since the Permian have been reconstructed in some detail.

Continental drift is an important factor influencing biographic distribution. For example, the difference between the faunas of the northern and southern Indonesian Islands is explained by the fact that the two regions have separate tectonic histories and have only recently come into close contact.

Figure: the world has been divided into six main biogeographic areas, according to the similarity of their animals. The discontinuity between the Australian and Oriental regions observed in the Indonesian Islands is called Wallace's Line.