Modern civilization has extremely deleterious consequences in regards to species richness, primarily through destruction of habitat. Because of these negative aspects of modernity hunter-gatherers have been idealized as a model of humanity at equilibrium with their ecology. 1491: New Revelations of the Americas Before Columbus lays out the revisionist, and to some extent now mainstream, argument that the American wilderness which European settlers encountered was actually an instance of “re-wilding” in the wake of native demographic collapse due to disease. But setting this case aside, what about Australia? Its fauna was even more exotic to Eurasian sensibilities, and the Australian Aboriginals do not seem to have ever shifted away from obligate hunter-gatherer lifestyles. Perhaps they truly were at equilibrium with their environment, judging from the fact that Australia has so many endemic species.
I think the argument that Australian Aboriginals were at some equilibrium is correct; but only because the havoc that they wrought upon the native ecosystem was relatively deep in the past. The particular destructiveness of modern civilization is a function of its progressiveness and the constant roil of its development. Pre-modern societies characterized by Malthusian conditions whereby population growth was “checked” by natural limitations were static enough over the long term that after an initial transient period of ecological instability a new equilibrium had time to settle in. If humanity is an environmental condition, Malthusian humanity is like a storm which passes. Post-Malthusian humanity is like a perpetual hurricane.
A new paper in Science speaks to the specific case of Australia. And Then There Were None?:
Giant marsupials, reptiles, and flightless birds once inhabited Australia (see the first figure). But 23 of the 24 genera of these megafauna disappeared in the late Pleistocene (125 to 12 thousand years ago). Most Australian megafauna appear to have survived until 51 to 40 thousand years ago, with human impact by hunting or vegetation change proposed as the extinction drivers…Yet, one site has stood out as an anomaly: Cuddie Springs in interior New South Wales. Persistent claims have been made that this site contains megafauna fossils associated with stone tools in sediments deposited 40 to 30 thousand years ago…thus indicating prolonged overlap between people and megafauna. These claims have been challenged…based on concerns about possible reworking of fossils from older deposits. To resolve this conundrum, Grün et al…have now directly dated the fossils themselves. The results provide no evidence for the late survival of megafauna at the site.
Here’s the original paper on the Cuddie River site, ESR and U-series analyses of faunal material from Cuddie Springs, NSW, Australia: implications for the timing of the extinction of the Australian megafauna:
The timing and cause of late Pleistocene faunal extinctions in Australia are subjects of a debate that has become polarised by two vigorously defended views. One contends that the late Pleistocene extinction was a short event caused by humans colonising the Australian continent, whereas the other promotes a gradual demise of the fauna, over a period of at least 10-20 ka, due to a combination of climatic changes and ecological pressures by humans. Cuddie Springs is central to this debate as it is the only site known in continental Australia where archaeological and megafauna remains co-occur.
We have analysed more than 60 bones and teeth from the site by laser ablation ICP-MS to determine U, and Th concentrations and distributions, and those with sufficiently high U concentrations were analysed for U-series isotopes. Twenty-nine teeth were analysed by ESR. These new results, as well as previously published geochronological data, contradict the hypothesis that the clastic sediments of Stratigraphic Unit 6 (SU6) are in primary context with the faunal, archaeological and other materials found in SU6, and that all have ages consistent with the optically stimulated luminescence (OSL) estimates of 30-36 ka. These young OSL results were used to argue for a relatively recent age of the extinct fauna. Our results imply that SU6 is either significantly older than the OSL results, or that a large fraction of the faunal material and the charcoal found in SU6 was derived from older, lateral deposits.
Our U and Th laser ablation ICPMS results as well as the REE profiles reported by Trueman et al. [2008. Comparing rates of recystallisation and the potential for preservation of biomolecules from the distribution of trace elements in fossil bones. C.R. Palevol. General Paleontology (Taphonomy and Fossilization) 7, 145-158] contradict the interpretation of previously reported rare earth element compositions of bones, and the argument based thereon for the primary context of faunal material and clastic sediments in SU6 layers.
ScienceDaily has more. Truly veni, vidi, vici is the story of man. The difference with modern man is that the exponent for the last two comes from 1 to ∞. We arrive. And see & conquer. We see & conquer. We see & conquer….
Citation:
ESR and U-series analyses of faunal material from Cuddie Springs, NSW, Australia: implications for the timing of the extinction of the Australian megafauna, doi:10.1016/j.quascirev.2009.11.004
And Then There Were None?, Science 327 (5964), 420. [DOI: 10.1126/science.1185517]
Note: The arrival of the dingo in the past 10,000 years to Australia resulted in a second wave of extinctions, the “Tasmanian Tiger” was extant on mainland Australia until about 2,000 years ago. Tasmania was separated from the Australian mainland before the arrival of the dingo, ergo, the persistence of large carnivorous marsupials down to modern period.
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