[ExI] Left Behind

[BillK]

On 5/23/09, Harvey Newstrom wrote:
>  Evolution is not a conscious process that tries to increase reproduction
> rates and the survival of genes.  Evolution is a random mutation process
> with no goals.  It is merely a statistical side-effect that random mutations
> increasing reproductive rates tend to out-complete less reproductive
> mutations.  Therefore, it is a mistake to ask why evolution did something or
> didn't do something.  These things happen randomly.  The real question we
> should ask is if a particular mutation increases or decreases reproduction
> rates.  Rephrasing the question to a non-anthropomorphic form usual
> clarifies the situation.
>
>  In this case, we shouldn't ask why masturbation evolved to feel good.  It
> simply was a random mutation that caused genitals to feel pleasure when
> stimulated.  From that starting point, it is obvious why this mutation would
> lead to both increased reproduction and increased masturbation, since both
> feel good.
>
>  A related question, that Robin may have been implying, is why didn't
> evolution produce genitals that feel pleasure during reproductive sex but do
> not feel pleasure during nonreproductive sex.  This would have required a
> much more complex mutation to detect and distinguish between fertile and not
> fertile stimulation of the genitals.  Statistically speaking, the simpler
> mutation that leads to both reproduction and masturbation would likely have
> evolved first.  Since most animals will not choose masturbation over a
> chance sexual encounter, the later mutation would probably not have
> increased reproductive rates anyway.  It would have required more complexity
> for no added reproductive rate.
>


Yes, we always have to remember that evolution is random kludge built
on random kludge built on random kludge. What was a good adaption for
a sea-slug is not such a good idea when used as part of the structure
of a human.

I also find fascinating the idea of 'spandrels'.
Quote:
This argument is used by Gould and Lewontin to explain some
aspects of evolution which they do not feel can be accounted for by
natural selection. Epiphenomenal spandrels are seen as those which exist
but are of no real interest, such as the redness of blood, the V-shaped
space between a pair of fingers or the fact that there are a
prime-number of digits on each limb. Such spandrels have no direct
relevance to any behaviour or function and give no clues as to whether
the structures that they are associated with were shaped through natural
selection.
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BillK