I am writing to supplement my response to Del Ratzsch of earlier today.
I dismissed some of his concerns out of hand. Specifically:
>I don't think that that is quite right. In a stable situation where the
>only variations are in the direction of reduced fitness, all the above
>may be true, but natural selection will act only as the "executioner of
>the unfit", and there will be no evolutionary movement - not even
>microevolution - at all. In fact, Darwin was stymied by that fact for
>some time.
So in order for evolution not to have occurred God would have had to
create a stable situation where all of the current traits of a creature
were optimum. Such a system would allow no change over time. Not even
cyclical change, unless it was on a time scale much shorter than the
generation time. Is this really a credible scenario?
>In any case, the above four do not "mathematically" entail
>microevolution.
True but the only additional required condition is the existence of a
survivability or fitness gradient.
In Christ,
robert van de water
associate researcher
UCLA