From: bear@tigger.cs.Colorado.EDU (Bear Giles)
Subject: Re: Facts and Values (was Where it came from)
Organization: National Oceanic & Atmospheric Adminstration / Boulder Labs
Distribution: na
Date: Wed, 26 Aug 1992 19:21:10 GMT

In article <25775@dog.ee.lbl.gov> sichase@csa3.lbl.gov writes:
>In article <1992Aug25.233552.29594@colorado.edu>, bear@tigger.cs.Colorado.EDU (Bear Giles) writes...
>> 
>>For instance: compare the species killed since the last ice age (saber-
>>tooth tigers, mammoths, lions (in Europe), great bears, the horse in
>>the Americas (if not the horse, some large mammal was killed off by
>>humans in the Americas in prehistory), etc.... to the effort being spent
>>keeping many species alive today.
>
>I think that this is a common, but completely misleading interpretation
>of the facts.  Now, ecology is poorly understood.  Simple questions like
>why the tropics are biologically more diverse than colder regions and
>why aquatic food chains are longer than those on land are not well 
>understood.  But there are some things which are known.  Species tend
>to have lifetimes on the order of 10 million years.  Speciation and 
>extinction tend to work on the same timescale, resulting in diversity 
>which is constant on timescales shorter than say, 1 million years (aside
>from extinction events.)  

I thought there was a _lot_ of evidence that early humans hunted many
other animals to extinction.  Bones in fire pits and the like.

(By that I mean the local population appears to have declined in
numbers directly related to the apparent hunting activity of the
early humans.  The animals did not simply die when humans arrived,
they were hunted to extinction).

>But we, cutting off our collective nose to spite our face, are seriously 
>reducing the number and diversity of species on our planet on a time 
>scale of decades, not millions of years.  We may in fact be instigating
>the greatest extinction event of all time.

I think you understate the earlier extinctions.  We would have to 
sterilize the entire land surface and kill all marine life more complex
than planktons to get near some kill-offs.  (The development of oxygen
producing plants was one such kill-off, and I seem to recall there was
another one as well (due to a _big_ asteroid hit, perhaps?  This was
a _long_ time before the dinosaur kill-off, btw)).

Anyway, I'm _not_ saying our current actions aren't cause for concern.
What I am saying is that some "ecological" solutions are _far_ worse,
and that there is historical evidence to back that claim.

A return to a "simpler" life will eventually reduce humanity's effect
on the environment -- because the environment will not support the current
population and you'll have massive die-off from starvation, malnutrition
and pestilence.  And war, knowing human history.

But before 5 billion odd humans die (still leaving more people alive
than at any time before this millennium), they can cause a _lot_ of
damage.  Imagine a plague of locust, then toss in modern weaponry.

>Just because species have gone extinct without our help does not mean that
>it is morally right, or in our own best interest, to wipe out millions
>of species (and thousands of mammal species) in the span of a hundred years. 

I didn't think there were "thousands" of mammal species to begin with, and
"millions" of species seems a little high as well.


Bear Giles
bear@fsl.noaa.gov