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Re: Permian Extinction....



I am not sure if I remember correctly, but a girl at a coffee shop showed me
this months Discover which had an artiicle in which I believe the latest
theory is the increase of Carbon Dioxide in the atmosphere and dissolved CO2
in bodies of water started a "cascade failure" in the food chain, starting
with plankton which are sensative to high CO2 (inteferes with use of calcium
and shell formation). The destruction of plankton populations apparently
sent a "shockwave" through the rest of the planets ecosystems. If this is
true....the future looks bleak since it has already been shown that plankton
populations are dying off!

dlessin@accesschicago.net

-----Original Message-----
From: John M. Dollan <dollan@cyberport.net>
To: Dinosaur Mailing List <dinosaur@usc.edu>
Date: Monday, August 10, 1998 4:01 AM
Subject: Permian Extinction....


>Okay, so while we're on the subject....
>
>What are some of the leading theories for the Permian extinction?  From
>what I've inferred from my various (and in some cases, hoplessly
>outdated) reading, during the Permian Pangea was in full form, and the
>typical continental climate was rather arid.  In the Triassic, Pangea
>was breaking up, and the climate was growing wetter...I think.  If this
>is the case, wouldn't that promote diversity, rather than cause
>extinctions?  If I'm wrong, then what was up with the continetns?
>
>How about an ice age?  Changing ocean currents...a combination of many
>things?  After all, when 90% or more of the life forms on a planet die
>off, some must be going on that's pretty noticable.
>
>We'll exclude an impact from this scenario, since there seems to be no
>evidence for one as of yet (although, as they say, lack of evidence does
>not mean there is none...yet).
>--
>John M. Dollan
>Montana State University-Northern
>Graduate Assistant
>http://www.geocities.com/Athens/Academy/1861/
>ICQ# 308260
>
>"To make an apple pie from scratch, you must first create the
>universe...."  Carl Sagan
>