Here is a brief synopsis of the origins of the Aborigines

The Aborigines began arriving on the north coast of Australia
approximately 75,000 years ago. They mostly came in boats from Southeast Asia.

They also might have come from Indonesia because there is only 110miles of water
separating the two continents (and that water is on a shelf that maight have even been
a land bridge at some point.

The Aborigines have been living uninterrupted in Australia for the longest of any civilization,
almost 40,000 years!!!