NY Times, December 22, 2009
Observatory
DNA Shifts Timeline for Mammoths’ Exit
By HENRY FOUNTAIN
Thousands of years ago in northwestern North America, large animal
species, among them the woolly mammoth and the horse, became
extinct. Among the proposed explanations for this is one known as
the blitzkrieg hypothesis — that humans entering the region
rapidly wiped the animals out through overhunting.
The validity of that explanation, and others, depends in parts on
the timing of the extinctions. How many thousands of years ago did
the animals disappear?
Until now, the answer to that question has been 13,000 to 15,000
years ago. But those dates come from the youngest reliably dated
fossils that have been found, and who is to say there aren’t even
younger fossils out there?
A new study has come up with a far different answer, using a far
different technique.
Rather than dating actual fossils, the researchers analyzed DNA
found in permanently frozen sediments at a site on the Yukon River
in central Alaska. As they report in The Proceedings of the
National Academy of Sciences, they found evidence that mammoths
and horses were still around at least until 10,500 years ago, long
after humans arrived.
Earlier studies had shown that DNA from animals’ waste, skin cells
and hair could be preserved in permanently frozen sediments.
James Haile and Eske Willerslev of the University of Copenhagen
and colleagues analyzed samples taken from the frozen soil at
various depths, corresponding to about 8,000 to 11,000 years ago.
Since humans were known to arrive in the region at least 14,000
years ago, the finding casts doubt on the blitzkrieg hypothesis.
Hunting may have contributed to the decline of these animals, the
researchers write, but it “did not deliver the deathblow.”
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http://louisproyect.wordpress.com/2009/06/15/the-woolly-mammoth-and-the-noble-savage/
Back in the mid-1990s when I first began writing about American
Indians and ecology, I was surprised to see how eager some
progressives, and even some Marxists, were to characterize the
Indians as just as wasteful as a modern corporation. Talking
points included bison being driven off cliffs, as well as the
earliest ancestors of modern Indians being responsible for killing
off the woolly mammoth and a number of other Pleistocene megafauna.
The extremely distinguished Marxist David Harvey wrote an
extremely undistinguished book called “Justice, Nature, and the
Geography of Difference” (nobody is perfect) that included these
talking points, including the following:
Archaeological evidence likewise suggests that late ice-age
hunting groups hunted many of their prey to extinction while fire
must surely rate as one of the most far-reaching agents of
ecological transformation ever acquired, allowing very small
groups to exercise immense ecosystemic influence.
Harvey’s citation for this is a 1956 article by Carl Sauer, a
geographer who has the distinction of being the first to put
forward the overkill hypothesis but it is really Paul S. Martin
who has become the most prominent defender. Martin, a U. of
Arizona geosciences professor emeritus, began writing about
Pleistocene extinctions and Clovis people’s sole responsibility
for the “blitzkrieg” in 1967. (The Clovis were “paleo-Indians”
named after the archaeological site in New Mexico where a
characteristic spear point was discovered.)
Unfortunately, very few of Martin’s articles are available online
except for those who have access to a research library, as I do.
If you want to read a fairly typical example, I would refer you to
the March 9, 1973 Science Magazine article titled “The Discovery
of America” in which he makes the case that overkill of large
herbivore mammals like the mammoth was made possible by the
beast’s failure to recognize man as a predator. Once the
herbivores became extinct, it was only a matter of time before the
carnivores—including the saber-tooth tiger—became extinct as well.
(clip)
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