Timing is a critical issue in the Pleistocene extinctions. The timings of human arrival in Australia, climatic events and the Pleistocene extinctions are all important in determining the causes of the extinctions (Furby, et. al. 1993:204). The date of human arrival in Australia is important in evaluating the influence of humans in the Pleistocene 'megafauna' extinctions. The prevailing date is around 40 000 BP, however Hiscock claims a date from artefacts at Malakunanja II in exces

The ecophysiological model relies on a rare and brief (almost catastrophic) convergence of poor conditions in the climate and environment. Like the other possible causes of the extinctions, the ecophysiological model is too restrictive with its chronological boundaries to be a definite solution. If the extinctions were greater at the glacial event, than this model would seem more plausible, but presently they do not appear to be concentrated at any time. More data is needed to fix the time of the extinctions (Flannery 1990:49), or a multivariate theory to accommodate the variety in the timing of the extinctions.

The ecophysiological model seems the most convincing explanation, but it does not consider previous Pleistocene climatic events that would have stressed the animals. The animals may have adapted to periodic climatic extremes, especially as the glacial periods were much longer than the interglacials (Hope 1984:70). Methodological concerns are raised, as the studies sometimes used very small sample populations (Archer 1984:154). There are also other studies that show megafauna and the equivalent dwarf species both reducing in size, when they are supposed to be the same species in succession, with the dwarf species not changing size (Archer 1984:154). This explanation takes little notice of human contribution to the extinctions. It is possible that the Pleistocene fire regime that was perpetuated by the Aboriginals may have regionally altered plant species that led to ecological pressure on the mammals, similar to the end-Cainozoic conditions. However, during the glacial event the Aboriginals may have stuck closely to the well watered coastal regions, and were probably as stressed as the megafauna (Archer 1984:154).

Overkill is where the Pleistocene fauna becomes extinct at the same time as humans populate Australia, as a result of direct hunting. This model says that the extinctions happened so rapidly that kill sites will be hard to find (Flannery 1990:50). The dwarfism is explained as a result of selective hunting resulting in a genetic shift in size (Flannery 1990:51). Evidence for the blitzkrieg is that no site yet has revealed extinct Pleistocene mammals with human occupation as early as 35 000 BP. However the amount of sites after 35 000 BP and up to 10 000 BP with human and megafauna remains weakens the model. There is also no published, undisputed account of humans actually hunting and eating megafauna (Rich 1984:997). It has been shown that humans and Pleistocene fauna coexisted for around 10 000 years (Horton 1980:94). The blitzkrieg model is not suitable as an explanation for the Pleistocene extinctions because of the existence of evidence against it.

Some common words found in the essay are:
Australian Pleistocene, Galloway Kemp, Overkill Pleistocene, , BP Hope, Pleistocene Macropus, BP Furby, BP Flannery, BP Mungo, Australia English, 000 bp, 18 000 bp, pleistocene extinctions, 18 000, et al, archer 1984154, white et, glacial event, extinctions occurred, ecophysiological model, white et al, catastrophe model, 35 000 bp, 40 000 bp, mungo lacustral period,
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