Australian Immigration and Its Effects Australia is an island continent which is geographically isolated from the rest of the world. This has resulted in the evolution of many unique plants and animals and the development of a very fragile ecosystem. This ecosystem has been influenced by human immigration for many thousands of years. The original immigrants were the Aborigines who are thought to have migrated to Australia from Asia between 50 and 100 thousand years ago. These primitive people learned to live in the inhospitable environment of Australia with very little effect. Their major environmental impact was from the use of controlled burning of the land. Ov