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Jurassic intelligence (time-scale for evolution of alien
Forwarded by Terry Colvin<firstname.lastname@example.org>/0712MST/1412GMT.
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Subject: Jurassic intelligence (time-scale for evolution of alien
Author: SKEPTIC Discussion Group <SKEPTIC@JHUVM.HCF.JHU.EDU> at smtp
Date: 10/5/1995 7:09 AM
Martin Adamson says that dinosaurs had been on
>earth for 150 million years and didn't (as far as we can tell) evolve
>advanced intelligence. Mammals have been the dominant type for 60 million
>years, and have evolved intelligence. So time is not by itself sufficient
>to evolve intelligence, there needs to be another set of circumstances....
>There is a good discussion of this issue in Jared Diamond's The Rise and
>Fall of the Third Chimpanzee. He thinks intelligent life is a very
>remote possibility. His point is that life on earth has existed for 3.5
>billion years, and intelligent life has evolved only in the last 150,000.
I'd pointed out that it wouldn't make much difference from a time-scale
point of view if the dinosaurs _had_ evolved intelligence:
>Well, the Jurassic period started less than 200 million years back,
>so we'd be shaving maybe 5% off the estimate. ...
and I'd go further than that: even if the first trilobites and jawless fish
had been intelligent, it took nearly all of those 3.5 billion years to get
that far. Of course that 3.5 billion is itself a pretty loose estimate,
which I don't see in Diamond---I just reread the "Alone in a Crowded
Universe" chapter. Martin, don't you mean "4.5 billion"? as in
"the earth is 4.5 billion years old, so multicellular life of modern
design occupies little more than 10 percent of earthly time."
Gould, _Wonderful Life_, p56
Almost all of our evolution-time was spent getting to a point from which
we took off, tried various complex patterns such as fish, octopi, birds,
dinosaurs, mammals...and we achieved intelligence, and radios, quite quickly
in stellar-age terms. I don't think Diamond's chapter is really on-target:
the evolutionary precursors of radios (or other complex technology) are
indeed indicated by Jurassic fossils, we call them "brains" and "eyes" and
stuff like that.
I won't be surprised if we go out into space and find lots of planets in
which the Cambrian explosion never happened, because I haven't the slightest
idea why it happened here or why it took billions of years for bacteria to
get together. I will be surprised if we find multicellular life with
organized nervous systems which is more than a billion years old and yet has
not developed intelligence. It seems to me that we came close lots of times,
and if we hadn't hit it with people we would have hit it sooner or later
Tom Myers email@example.com