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Re: mass extinction





Dann Pigdon wrote:

On Mon, 20 Mar 2006 19:57:03 -0500, Jeff Hecht wrote


That's an important part of the evidence that humans were linked to the Pleistocene extinction -- our widespread presence was something that differed from prior interglacials.



In cases like New Zealand, megafaunal extinction was very rapid after the introduction of feral primates, and their activities can probably be blamed. However in other areas (like Australia) where there was a long coexistance (tens of thousands of years), those pesky primates certainly weren't the sole reason for megafaunal extinction. They may not even have been the main reason.


No doubt hunting activities and land clearance didn't help, however middle-
class guilt and political correctness are not good reasons to lump the blame entirely on us poor maligned hominids. We're not *completely* evil. :)





Well said, Dann. A recent summary of the issues involved with extrapolating primate-induced extinctions on islands to continents (such as Australia) can be found in:


Wroe, Field, and Grayson, 2006: Megafaunal extinction: climate, humans and assumptions. TREE, 21(2): 61-2

which reminds us that "islands are not continents writ small"... I have a pdf is anyone is interested.

The distinction between hunting/habitat clearance and climate change as primary agents of megafaunal extinction is important over here for reasons that go beyond trying to understand how the world works. The thesis that Aboriginal Australians were primarly responsible for the extinctions has reportedly been used to marginalise Traditional Owners from land management practice in some situations. And as long as Aboriginals remain the 'prime culprit' for the extinctions, the 'head in the sand' lobby (i.e. those hostile to the idea of human induced climate change) don't have to face up to the idea that climate change can cause extinctions (remember that the Australian governement is alone in the developed world with the US in refusing to ratify Kyoto and in refusing to consider any climate change 'solution' that does not explicitly benefit Big Coal). The net result is that the 'scientific' debate on megafaunal exinctions in Australia has become extremely heated and politicised - but as Dann says, those of you overseas should understand that not everyone here believes that the first Australians knocked out the megafauna. Some of the stories of the backstabbing that goes on are extraordinary... makes me glad I work on the Mesozoic.. :-)

Cheers
Col


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