[extropy-chat] Two Errors: Intelligent Design and "Progress"
robert.bradbury at gmail.com
Sun Jan 22 11:59:54 UTC 2006
I read this note a few weeks ago and found the arguments weak.
"Crucially, the general trend toward greater complexity in earthly life is
not the result of some *direction* to evolution; it's the result of random
drift taking place in the absence of mass extinctions."
Actually that isn't true. There are at least two "directions to evolution"
that I can think of. The first is towards a direction of greater
survivability. There is a second direction which seems to be to increase
the rate of evolution "when necessary".
The direction towards greater survivability can clearly be seen in both the
development of flight and the development of intelligence. Both enhance the
chances of the survival of the species (and its genes). If one looks at
everything from the development of the E. coli SOS response to the
development of the nucleus, chromosomes and sex it looks like evolution has
two competing priorities. First, "if its not broke don't fix it". This is
why the SOS response isn't turned on by default in E. coli. (The SOS
response allows hypermutation and takes place when E. coli is stressed --
presumably the stress indicates a situation where the genome may not survive
and the only solution may be to rapidly evolve a better genome.) That leads
to the second direction which is to detect cases where the genome may be
"maladapted" and evolve it quickly. Things like chromosomes and sex allow
for genome redundancy (not generally present in prokaryotes) so you can vary
things and have a backup copy. They also allow you to mix and match gene
sets with the possibility of creating a new species perhaps better suited
for different environments.
Influenza is a great example of a rapidly evolving species due to its
multiple "chromosomes" that doesn't care about genome redundancy --
presumably because it is always up against an adapting immune system trying
to eliminate it. HIV is an example of a rapidly evolving species with a
built in strategy of hypermutation assuming that some small percentage of
the copies will survive. Viruses can get away with such strategies because
they aren't paying most of the cost of making genetic copies. More complex
organisms from bacteria up to mammals have to take into account the high
investment costs of creating a copy. If the copy fails, the investment is
completely wasted. This may be one reason for the development of
intelligence -- the creation and selection of survival strategies
(behaviors) is taking place in software rather than hardware.
Ideas are cheap -- maybe thats why we have so many stupid ones floating
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