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Re: fHuman vs. natural influences on the environment



In article <jscanlon-1308962149360001@sp63.linex.com>,
   jscanlon@linex.com (Jim Scanlon) wrote:

>Individual adaptation and species adaptation are much 
different on a
>vastly different time scales.

The two are very much related.  A species that hasn't adapted 
much in long time periods hasn't had much adaptive pressure 
applied to it.  Some of those same bacteria were exposed to 
penicillin, and they became resistant over a 30-40 year 
period.

>Some species change, or evolve and turn into something else. 

Whether species evolve into other species is still debatable. 
Very few "missing links" have been found to substantiate this 
claim.

Others hardly
>change over millions of years like bacteria, or the 
horseshoe crab. Some
>change very radically and lose functioning organs (i.e. 
degenerate) in
>adapting to their environment like so many parasites.
>The wretched inhabitants of the ruins of Imperial Egypt and 
the
>descendants of the Mayan Kingdoms adapted and survived to 
reproduce.
>That's the way "nature" works: whatever it is that survives 
is the
>fittest. Fitness can only be determined by humans in 
retrospect.
>From what I understand about mass extinctions, they are 
caused by radical
>changes in the environment, which is to say habitat. These 
radical changes
>do not usually occur suddenly or that often. Our earth is 
undergoing
>several kinds of simultaneous rapid, radical change right 
now. 
>It may be impossible to alter these changes, but it seems to 
make more
>sense to at least try to do something reasonable,  rather 
than just let
>nature (or "the market") take its course.
>Best wishes, 
>Jim Scanlon
>

As I replied in an email message to you, most of the species 
that have ever existed are now extinct, and they went extinct 
before man ever walked on this planet.  We shouldn't 
deliberately drive species to extinction, but we also 
probably should not intervene to prevent species from going 
extinct that are not fit for survival.

A good example of this is the cheetah in Africa.  Scientific 
American ran an article on this species, in which it was 
noted that their genetic diversity is very small, and they 
are currently experiencing reproductive problems.  This 
species is probably not fit to survive long term, and it may 
not even be possible for us to ensure this if we wanted to.  
In other words, how would some researcher go about 
introducing enough beneficial "defects" in their genome to 
ensure enough genetic diversity to take care of this species 
over geologic time frames?  We have no way of knowing the 
answer to this one without being able to anticipate what kind 
of future adaptive pressure they will face, nor do we have 
the expertise to modify their genes.


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