Ancient Radiation levels

["Karam, Andrew" <Andrew_Karam@URMC.Rochester.edu>]

-----Original Message-----
From: Martin Fraser

'Lower' forms of life have been evolving for as long as they've in
existence. (-snip-)  they are every bit as sophisticated or
unsophisticated as apes or snails.  

================
Dear Martin,

Lynne Margulis and Stephen Jay Gould have both made similar observations.
On the other hand, Schopf, in his recent book Cradle of Life points out that
some of the most ancient organisms on Earth may have evolved only slightly
in 3-3.5 billion years, basing this on fossil morphology, stable isotopic
evidence, and other factors.

This does bring up another interesting point, however.  Mutations don't
necessarily mean the same thing to all forms of life.  For us, a changed
gene may lead to death while, to the flu virus, it is how they survive to
infect again.  Fatal mutations (at least, those that are fatal before an
organism can reproduce) are invariably not passed on, but sublethal
mutations are.  At what point (or complexity in life) do mutations do more
harm than good?

Andy
(andrew_karam@urmc.rochester.edu)

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