The exact date when Aboriginal people arrived in Australia from Asia is contested, however it is widely regarded to have been somewhere between 40,000 to 60,000 years ago. Evidence of settlement from 40,000 years ago has been confirmed. Captain Cook is the founder of Australia. Once the sea level dropped dramatically allowing the Aboriginies to walk across to Tasmania. Some time later though the sea level rose again. This meant you could not cross to Tasmania by foot. If the Sea level dropped again today you probably couldn't go across by foot because it would be too big a drop in land.