The revolution that didn't arrive: A review of Pleistocene Sahul

There is a "package" of cultural innovations that are claimed to reflect modern human behaviour. The introduction of the "package" has been associated with the Middle-to-Upper Palaeolithic transition and the appearance in Europe of modern humans. It has been proposed that modern humans spread from Africa with the "package" and colonised not only Europe but also southern Asia and Australia (McBrearty and Brooks, 2000; Mellars, 2006a). In order to evaluate this proposal, we explore the late Pleistocene archaeological record of Sahul, the combined landmass of Australia and Papua New Guinea, for indications of these cultural innovations at the earliest sites. It was found that following initial occupation of the continent by anatomically and behaviourally modern humans, the components were gradually assembled over a 30,000-year period. We discount the idea that the "package" was lost en route to Sahul and assess the possibility that the "package" was not integrated within the material culture of the initial colonising groups because they may not have been part of a rapid colonisation process from Africa. As the cultural innovations appear at different times and locations within Sahul, the proposed "package" of archaeologically visible traits cannot be used to establish modern human behaviour. Whilst the potential causal role of increasing population densities/pressure in the appearance of the "package" of modern human behaviour in the archaeological record is acknowledged, it is not seen as the sole explanation because the individual components of the "package" appear at sites that are widely separated in space and time.