On Sep 18, 2005, at 5:23 PM, Ronn!Blankenship wrote:
At 07:09 PM Sunday 9/18/2005, Warren Ockrassa wrote:
What many might not grasp is how very much time is actually required.
It "only" took 500 MY for life to go from trilobites to us, but 500
MY is a tremendous amount of time that really can't easily be
understood in human terms. Given time enough, evolution from one
species to another can happen and has in truth been recorded in
fossil records for large organisms — however inconceivable it might
seem to some.
"Only" is applicable in the sense that from the Cambrian "explosion"
to the present is <15% of the total age of the Earth, and trilobites
are even more recent.
Yeah — deep time. It's really pretty humbling to contemplate the range
of time that's been necessary to produce the planet and the life that
exists on it. We're really only beginning to understand a lot of the
processes involved and how they interact with one another.
For instance on another list there's been sporadic discussion of ways
in which hurricanes might be diffused before landfall, or even before
they develop — which sounds good from an inundated-city perspective,
but it's easy to overlook the way hurricanes appear to factor in —
heavily — with marine life. That is, by trying to stop hurricanes, we
could end up wreaking tremendous havoc on the ocean's ecosystem, and if
we do that, if we do enough damage to the seas, we've had it.
Or if you look at the Colorado River and the way it's been dammed, you
see that all these engineering projects which looked so good in the
last century have had some very negative effects on life and the
ecosystem of the deserts. The Colorado used to flow all the way into
the Baja, and now it trickles to a dry wash miles away from the sea.
Also, the periodic flooding the Colorado used to have recharged inland
aquifers, allowing riparian areas to flourish in the Mojave and Sonora
desert regions. But those riparian areas are now drying up, because
they're not getting the water they need to sustain themselves.
I used to think that if you visited Earth 1000 years from now you'd
find no immediate trace of human habitation (think a global survey from
orbit), either because we'd have wiped ourselves out or we would have
figured out how to exist in a more harmonious but still technologically
advanced way with the biosphere. I'm thinking now that's not so likely.
After all we have goats to thank for lots of the Sahara — goats led in
by humans. Even if our cities are all gone and rotted into the
substrate, we'll have left footprints, some of them probably quite
large.
But all of that is absolutely nothing contrasted to deep time. And
sometimes it can be instructive to remember that our species will
eventually cease to exist. Either we'll all kill ourselves or — no
matter what — gene drift and evolution will continue and we'll
eventually have a creature that cannot interbreed with our current
stock. When that might happen is hard to guess, but it's certain that
it will. Homo sapiens as we know it today is doomed, like 90%+ of all
other terrestrial species, to extinction.
--
Warren Ockrassa, Publisher/Editor, nightwares Books
http://books.nightwares.com/
Current work in progress "The Seven-Year Mirror"
<http://books.nightwares.com/ockrassa/Flat_Out.pdf>
<http://books.nightwares.com/ockrassa/Storms_on_a_Flat_Placid_Sea.pdf>
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