Australia before people started recording events on stone and paper. "The spread of people to Australia" una investigación en curso en un refugio de roca Australia at least 50,000 years at least 50,000 years debate at least 50,000 years a theory now highly disputed The spread of people to Australia debate The spread of people to Australia "The spread of people to Australia" "The spread of people to Australia" made that crossing The spread of people to Australia at least 50,000 years a theory now highly disputed