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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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