On Tue, 26 Oct 2004 05:47:39 +0000 (UTC), Catherine Woodgold 
 wrote:

> Erwin Moller (since_humans_read_this_I_am_spammed_too_much{at}spamyourself.com) 
> writes:

>> One sidenote: For evolution to work you need environmental pressure. 

This is not correct. Populations will evolve even if the environment is
perfectly stable. There are two important reasons why this is so. First,
a large part of evolution is due to random genetic drift and "environmental
pressure" is irrelevant for this mechanism of evolution. Second, no species
is perfectly adapted to its environment. There's always room for further
adaptation. (Do you know of any species that has stopped evolving because
it has become perfectly adapted to its present environment?)

>> We humans have a way of making our complete environment to fit our needs. 
>> We also take care of all sick fellowhumans with medical care.
>> 
>> I am not oposing to that (being human myself), but it reduces the 
>> environmental pressure a lot by the use of our technology. In a certain 
>> sense we are so on top of our environment, that our evolution slows down. 
>> Ironical, isn't it?

What's "ironical" is that your conclusion is completely wrong. Because of 
advances in medicine etc. we are causing the rate of human evolution to speed 
up, not slow down. In the past, certain individuals with genetic diseases
(for example) would be eliminated from the population because we didn't
have the technology. Today (in industrialized countries) these individuals
survive and reproduce. Thus, the genes they carry have a chance of spreading 
in the human population and this is what evolution is all about. As a general 
rule, when negative selection is relaxed evolution speeds up.

Your conclusion seems to be based on a misunderstanding of evolution. You
focus too much on positive natural selection as a mechanism of evolution
and you assume that we have become so well-adapted our present environment
that further adaptation isn't happening.

> Just because we have medical care doesn't mean we're
> not evolving.  For one thing, medical care can only do
> so much.  Vitamins have much more effect on health and
> length of life IMO.  Anyway, we are evolving to promote --
> what?  intelligence?  A collection of humans that incluces
> a minimum number of creative people?  A collection of
> humans who care about each other -- or who don't care?
> People who are careless about birth control, or who
> love children?  There are environmental pressures -- 
> just different ones from before.

Cathy, you also seem to be focused on positive natural selection as the only
significant mechanism of evolution and you seem to accept the idea that 
we have no room for adaptation to our present physical environment. You
shouldn't have conceded Erwin Moller's conclusion since it's incorrect.




Larry Moran
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