In article <jh07a4d7oohrrc6i6tn78aa8niaeng097q@4ax.com>,
 Chris L Peterson <clp@alumni.caltech.edu> wrote:

On Wed, 13 Aug 2008 17:12:57 -0700, "K_h" <KHolmes@SX729.com> wrote:

This contradiction can be resolved if the origin of life is far harder than 
commonly believed...

My thinking is that life is easy, and probably common. It's the part
about it becoming (technologically) intelligent that's more likely to be
difficult and rare.

I see nothing to suggest that there are many species on Earth poised to
become technological given a few million years of evolution. Most
species have been around and stable for at least that long. Given the
vast numbers of species on Earth, living and extinct, and the presence
of only one technological one- which happens to be of very recent origin
and likely on the edge of extinction itself- that seems like the weak
link in the Drake chain, and therefore a reasonable answer to the Fermi
Paradox.

I suspect that just as when one system of biochemistry establishes the 
pattern of life, things that use it will eat anything else that shows 
up, it is likely that when one highly intelligent species shows up, it 
will limit the opportunities for anything else to evolve into sentience. 

The final events that drove human evolution to intelligence were all 
climatic changes. For example, when forests of Africa became savannah, 
the apes that lived there had to adapt, and they ended up going down the 
road to high intelligence. It's interesting to note that this also 
happened only in once place, and then humans spread out to everywhere. 

There are plenty of species running around on the Earth now that are at 
about the level of intelligence of our ancestors, oh, twenty million 
years ago. They're not likely to develop to sentience any time soon, and 
certainly not while we're around unless we help them. (David Brin has 
written science fiction novels around that concept ... in his universe 
we're a rare event, independently developed sentience. That causes a lot 
of political trouble for us in the interstellar culture.) But if we were 
to off ourselves suddenly, the Earth would heal and something might have 
a chance to develop sentience.

-- 
Timberwoof <me at timberwoof dot com> http://www.timberwoof.com
People who can't spell get kicked out of Hogwarts.