Evidently under the destabilizing circumstances of colonization, those who discover new lands ignore accompanying extinctions. Damage control, if any, comes later. The first few hundred years of prehistoric colonization on a pristine continent or island may be not unlike the last few hundred years in America in terms of increasingly destructive economic practices, as viewed by a prudent resource manager.
From the perspective of radiocarbon dating, we glimpse 40,000 years of prehistoric global extinctions with mounting unease bordering on horror. Half of the global megafauna was lost, a rich assemblage of large and beautiful mammals, never to ‘bear the burden of our thoughts’, as Thoreau imagined. Perhaps as many as one quarter of the birds of the world vanished. Not all the wreckage necessarily reflects prehistoric human activity. But the closer we come to the present, the stronger the case for human involvement, and the future only portends vastly more of the same at rapidly accelerating rates of loss.
Given the present global condition of a seemingly insatiable appetite for goods fueled by a runaway technology and its accompanying pollution, it is hard not to imagine that the Cenozoic can overtake the late Cretaceous as a time of sudden and sever extinction, this time triggered by the ‘human bolide’ rather than one from outer space. It is by no means clear that post-Cenozoic recovery will occur as rapidly as post-Cretaceous recovery, which in some cases required millions of years. It is by no means clear whether the survivors will include our species, or even the type of global ecology we have belatedly come to value. Like the islands of doom in the Central Pacific, once inhabited and later abandoned after heavy extinctions of their native biota, we could become the ‘Planet of Doom.’ The biogeographic pathologies of the last 40,000 years, a mere moment in earth history, bear hallmarks of impending mass extinction.
40,000 years of extinctions on the ‘Planet of Doom’ Palaeography, Palaeoclimatology, Palaeoecology (Global and Planetary Change Section) 82 (1990) 187—201.
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