New Arrivals in Australia (image) Max-Planck-Gesellschaft Caption Four-thousand years ago, Australia was no longer connected to the mainland as it had been during the ice age. The immigrants thus crossed the ocean, arriving by boat. Credit Gunter Senft/MPI for Psycholinguistics Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.