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Re: RE: Extinction



The point about baby turtles withstanding supercooling by 
pulling into their shells (in C. picta) is interesting but
please dont pin all your hopes on one species of turtle.
Sea turtles cannot ,pull into their shells and studies in
the red-earred slider which can indicate the presence of
glycerine and glycerols or glycols which would act as 
cryoprotectants. Did this study you quote test for the
presence of these sugars in increased amounts?

Also the turtle supercooling hypothesis does not explain
the ability of the Northern Wood Frog or several other species
that have been found frozen, some spread-eagled, in a block
of ice and which have survived. This work has been well
publicized recently in Omni or Discover magazines --- cant
remember right now (with photos) although frog nuts like
myself have always known about it but couldnt explain it.
The work that was publicized also indicates the presence of
cryoprotectant substances in these frogs as a probable
explanation.

No, I dont think discussing the effect of temperature extremes
in today's animals from a physiological standpoint runs too
far afield from studying how or why the dinosaurs became 
extinct and why other species survived.  I dont know if
anything we find out today on an extant species has direct relevance 
to an extinct one but I do think it can be a part of the
equation that needs to be considered.  There are much more
pertinent  uses to which this work is being directed for
today's (and tomorrow's) needs in medicine and such.