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Re: Ice Age as a cause of mammoth extinction
In a message dated 97-12-24 03:01:41 EST, you write:
<< Anyways, I sat down to eat dinner, and there was this thing about
mammoth extinction on tv. Well, yeah, they did cover a lot more stuff
than just the Ice Age, but that's not really what I'm writing the
message about, and I only saw the last half, so I won't go into details,
but my mom that they had said the end of the Ice Age took only 10-20
years???? How could that have happened? Seems a bit hard to believe.
A misunderstanding, possibly?
Also, does anybody have any info on the 4ft-tall dwarf mammoth?
this has been on about a half dozen times in the past two years. And yet I
watch it every time it's on. It turns out that mammoths did not all go extinct
~10Ka as was previously thought and that the probably hung on in a small
ecological niche that was unique to wrangel Island. Similarly, the mammoths
evolved into a dwarf race that persisted until about 3.7Ka which is just after
the Pyramids were built.
dwarfism in this case was probably in responce to isolation from the main
"herd" of mammoths on the mainland following a retreat of glaciers and a
concommitant rise in sea level (ie Global Warming!). The population of
Wrangel island must have been such that there was jsut enough animals so as to
not deplete their resources too quickly, and it must have produced a refugium
whereby this population was able to adapt to the changes . Then about 3.7Ka,
they too could no longer adapt to continued change and finally succumbed.
About the _environmental_ consequences. It now appears that based mainly on
ice cores from Greenland and the Arctic and supplemented by tree ring data,
that climate has been highly erratic since the end of the last Ice Age ~10Ka.
The cause has yet to be fully understood but what appears certain is the fact
the last glacial retreat followed a rapid shift from cold to our present warm
trend which has persited for the last 5000 years give or take a century or two
for the 'Little Ice Age" of the 17th century. Similarly the data show that
global climates since the Ice ages show a slow cooling trend over centuries
culminting in glaciation followed by "rapid" or sudden shifts to a warmer
regime in just decades (interglacial periods). Also before the Global Warming
scare took hold, the consensus among many researches was at that time, that
our present time (1970's) was 1) an interglaial period and ,2) headed for a
near future Ice Age. Astronomical and solar data seem to corroborate this
scenario more solidly than the Global Warming bunch has proved their point. So
a caveat emptor is warranted here. There have been a number of good ppers in
Science that could be cited (I do not have them all handy). That and a little
knowledge of _sunspot_ activity and Milankovic phenomena can readily explain,
IMO, the current climactic trend. Similarly, El Ninos have been around far
longer than we have known about them and likewise seem to be related.
Thomas R. Lipka