Nature of extinction

Patrick Foley patfoley at
Sat Apr 27 23:14:32 EDT 2002

Dear fellow sinners,

The Pleistocene overkill hypothesis has lots of scientific support. You may
want to look at:

P. S. Martin and R, G, Klein 1984. Quaternary Extinctions a prehistoric
revolution. U of Arizona Press.

Donald Grayson is a respectable anthropologist and author of the excellent
1993 book on the recent ecology and anthropology of the Great Basin, The
Desert's Past. Smithsonian Institution Press. Nonetheless I think he is
wrong about the overkill.

My own completely unsupported speculation is that anthropologist Grayson is
biased by his unwillingness to recognize the "culpability" of Native
Americans in the NA overkill. Of cource Pleistocene extinctions occurred
with human colonization or technical development in Australia, Europe and
other places. In Africa the large beasts coevolved with us and found ways
to adapt. We shocked the other continents to death.

The best competing hypothesis for massive Quaternary extinctions is climate
changes. This is surely in part true. But it is hard to blame the complete
loss of camelids, horses and elephants in NA. Horses in particular are
pretty opportunistic, easily invaded much of the world from North America
(where they evolved), and easily reinvaded much of NA including the vast
grasslands and coastal areas which never were eliminated by ice age climate

When it comes to the extinction of large mammals and birds in the last
40,000 years or so, there is really only one thing to say ...

Mea culpa, mea culpa, mea maxima culpa,
Patrick Foley
patfoley at

Paul Cherubini wrote:

> My last post attempt got chopped off so I hope it works this time.
> Neil Jones wrote:
> > It is frequently cited that extinction is a natural process. (This is
> > usually done by the opponents of conservation.) However, in
> > reality surely the level of natural extinctions is utterly minuscule
> > when compared to those which are "man-made".
> I guess that depends on the time frame we are talking about.
> Take a look at this vegetation and glacial coverage map of Europe.
> It doesn't appear that many butterflies could have existed
> in England just 10,000 - 20,000 years ago.
> According to archaeologist Donald Grayson, one of the reasons
> people tend to embrace "man-made" vs natural causes of
> extinction (at least in the case of large mammals) has to do
> with "green politics" as explained below:
> A renewed assault is being made on the popular idea that the
> mass extinction of large mammals in North America around
> 10,500 years ago was the result of human hunting.
> The overkill hypothesis was first put forward more than a
> century ago and has been widely accepted for the past 30
> years. But it does not square with the known facts and has
> become more a faith-based credo than good science, said
> Donald Grayson, an archaeologist at the University of Washington.
> "One of the reasons people have glommed on to the overkill
> hypothesis is 'green' politics," said Grayson. "It plays to the
> Judeo-Christian theme that human beings are all-powerful
> and responsible for negative impacts on the environment.
> Paul Cherubini
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