Therefore using reliable dates derived from archaeological evidence, theories of the initial colonisation of Australia have been determined.
"Over the past three decades perceptions of when humans first colonised Australia have altered radically. In 1961 Mulvaney observed that the oldest secure radiocarbon date in undoubted association with human activities was from a site at Cape Martin in S.A., dated to less than 9,000 years ago". (Allen 1989: 150)
In 1970 Golson suggested first colonisation in the Pleistocene age. By 1972,
"Mulvaney's claim of 16,000 years had been doubled by a series of 9 dates for occupation sites round Lake Mungo in western NSW which ranged from c.24,000 to c.32,000 years ago". Elsewhere, dates approaching 35,000 years ago were published for the southwest Western Australian site of Devil's Lair, and in 1981 an antiquity of 38,000 years was claimed for artefact-bearing layers at Upper Swan River ... Whereas the known antiquity for humans in Australia quadrupled between 1960 and 1980, this increase in antiquity has levelled off in the present decade. Claims in the past 10 years or so for human sites older than c.35,000 have been few." (Allen, 1989:149-50)
In the 1990s however, two sites in the Northern Territory have pushed the dates for initial colonisation further back. Malakunanja II and Nauwalabila I (both dated using thermoluminescence dating have recorded the oldest dates so far. Malakunanja II had nine dates ranging from 100 years ago to 61,000 years. (Roberts RG, Jones R, Smith MA 1990, 1990a). Nauwalabila I had five dates, the three oldest ranging from 30,000BP to 60,000BP (Roberts et al 1990, 1994). Therefore it has been put forward by Roberts et al (1994:615) that "initial human colonization of the northern part of Australia took place between 53,000 and 60,000 years ago. We favour a date of c.60,000 years for first landfall.
Therefore, using reliable dates and dating techniques, derived from archaeological evidence, dates for the initial colonisation of Australia have been put forward approximately 60,000BP.
With new archaeological evidence continually being discovered, who knows what dates of initial colonisation may be offered by archaeologists in the future.