The Great Filter

John K Clark (johnkc@well.com)
Wed, 21 Aug 1996 13:06:55 -0700 (PDT)


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On Wed, 21 Aug 96 hanson@dosh.hum.caltech.edu (Robin Hanson) Wrote:

>I'm no expert, but from reading Crick I got the strong
>impression that prokaryotic cells are much less robust to
>extreme environments, and much better tuned to the
>particulars of Earth now.


I think the opposite is true. Prokaryotic cells are so simple that there is
less to go wrong with them and thus they can survive in conditions that would
kill any eukaryotic cell. Ancient bacteria live in hot springs near the
boiling point of water, and at even higher temperature in deep sea underwater
vents, the current record was living in water at 583 degrees F. Although hot
this water was not boiling because it was under very high pressure, nothing
can live for long in boiling water.

The bacterium Micrococcus radiodurans will thrive even after being exposed to
6.5 million rontgens of Gamma rays, 10,000 times less would kill a human in
minutes. I know of no eukaryotic cell that is anywhere near that tough.

John K Clark johnkc@well.com

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