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Re: Ozzy Emu omlettes at Lake Eyre? Eye-eye!




On Sun, 17 Jan 1999, Allan Edels wrote:

>     I suppose that the analysis indicated that the eggs were formed by
> healthy individuals, and did not show any problems that would be
> attributable to climate or diet changes.  Take away those factors, and the
> main one remaining is human intervention - especially at the time-frame
> indicated - i.e. near the time humans began to settle (or merely) use the
> areas where the birds lived.

Close.  The researchers did an exhaustive amount of collecting and dating
to ascertain the simultaneous extinction of Genyornis in all (tested)
locations.  This coincides with the best estimates of human appearance at
a time with no radical climatic variation.  They then go on to invoke
human-induced fire and its ecological disruption in seasons when there
would
normally not be fire.  This is speculation but it is clearly labelled as
such.  They also mention predation by humans.  My own speculation would
run hotter along that line, of course.  In any case, this apparent
instantaneous extinction is (as the accompanying article suggests) a slap
in the face to those who lately insist that extinctions are invariably
caused by physical not biological factors.  While recognizing that
different extinctions may be caused by different things, and most
extinctions are caused by many things--both physical and biological, and
that it is usually foolish to identify first causes, this study may have
implications for other extinctions, particularly the K/T.  At the very
least, it should give pause to those who are content with simplistic
causes explaining _patterns_ in extinctions.