Both geologic and climatic events helped to make Australia's fauna unique. Australia was once part of the southern supercontinent Gondwana, which also included South America, Africa, India and Antarctica. Gondwana began to break up 140 million years ago (MYA); 50 MYA Australia separated from Antarctica and was relatively isolated until the collision of the Indo-Australian Plate with Asia in the Miocene era 5.3 MYA. As Australia drifted, it was isolated from evolutionary pressures in the rest of the world. Other examples of island isolation include Madagascar, New Zealand, Socotra, the Galapagos and Mauritius. The geographic isolation of Australia created a sharp division between Australian fauna and Asian fauna at the Wallace line.