From: John Beckett 

"Geo"  wrote in message
news::
> This is where i have a problem with the "evolution tries all
possibilities"
> in that it never seems to try backtracking.

Backtracking IS tried. It's just that often going backwards in the sense
that you mean is almost always a losing strategy because everything else in
your environment has also evolved, and the current environment will be
different from how it used to be, and so is likely to be unfriendly to
older strategies.

Take something like the "normal" number of eggs that a bird lays
in one season. Evolution does continually test whether it is better to lay
one more egg or one less egg, so you may have an evolutionary trail where a
certain creature used to lay (say) 6 eggs, then 8, then 9, then 7, then 4,
then 6, then 8, etc. So, yes, backtracking is possible.

John

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