Climate shifts were probably responsible for the extinction of the mammoth and other species more than 10,000 years ago, not over-hunting by humans, according to new research published on Wednesday.
Radiocarbon dating of 600 bones of bison, moose and humans that survived the mass extinction and remains of the mammoth and wild horse which did not, suggests humans were not responsible.
"That is what this new data points out," said Dr Dale Guthrie of the University of Alaska in Fairbanks.
Hmmm. Infuriatingly short on what the paper actually says and I can't find it on Nature's site. But there's this:
"But contrary to that theory, my dates show numbers of bison and wapiti (elk) were expanding both before and during human colonisation," Guthrie explained.
His radiocarbon research, reported in the journal Nature, shows there was a 1,000-year different between the demise of the wild horse and the woolly mammoth which Guthrie said is inconsistent with other theories.
So it appears that some critter populations were expanding at the time of colonization -- which one wouldn't expect if gangs of ravenous hunters were wiping out everything in sight -- and that they weren't doing it all at once, which is what the Blitzkrieg hypothesis says. The Overkill proponents will, of course, counter that this doesn't absolve humans, they just did in different species at different rates, some not at all. But any really good set of dates is A Good Thing.
Will certainly be getting more play, so stay tuned. . . .
Update: And there's more here:
His results, published today in Nature, found no evidence to support the proposed explanations for the extinction. A disease would imply that many animals died off at once, which the fossil evidence does not show. Dr Guthrie also dismisses the other explanations. "Contrary to [the blitzkrieg] theory my dates show numbers of bison and wapiti were expanding both before and during human colonisation. So we know this was not a simple sequence of bison and wapiti replacing the extinct mammoth and horse," he said.
Instead, the researchers found that the change in climate 13,000 years ago, at the end of the Pleistocene epoch, meant the food available to mammals gradually changed. The increase in temperatures and moisture at the start of the present Holocene epoch encouraged plants unpalatable to horses and mammoths. "These new data show that while humans could have contributed to the Pleistocene extinctions of mammoth and horse, these two species and others were apparently less well adapted to the rise of northern Holocene ecological conditions, favouring to some degree the modern grazing species," said Dr Guthrie.
So he didn't really rue out humans at all, but at least the blitzkrieg model.