Bob,
I have a simple question: how do you distinguish extinction from the
factors I've noted and extinction from (genetic ?) senescence in the
fossil record? Adding the essential notion of genetic drift complicates
this problem even further. How many of your paradigm examples come from
the great extinctions? It is easy to come up with a logical possibility
that a criticism does not meet, but it is far more difficult to formulate
and demonstrate that it is relevant and functional.
I run across the problem in connection with theodicy. People say that God
would not have created a world with the death of children or the killing
of prey, etc. This is an emotional response because of the effect on
parents and the distaste for blood and guts. I recall the reaction of
kids taken on a field trip to a tuna packing plant. It took a long time
for some of them to eat fish again. But, without death, the world would
have to be static, to note only the most obvious problem. It's easy to
come up with an objection ("I don't like it" will do), but somewhere
between difficult and impossible to come up with a viable "improvement."
Dave
On Wed, 18 Apr 2001 06:35:41 EDT RDehaan237@aol.com writes:
>
> In a message dated 4/17/01 1:12:08 PM, dfsiemensjr@juno.com writes:
>
> << Senescence in species, especially, and to some extent in genera
> and
> families, seems to me to be obviously explainable in evolutionary
> terms.
> That organisms become better and better adapted to specific
> environments
> seems to encompass a good deal of evolutionary theory. However, the
> environment does not remain constant. I think of climate changes;
> plate
> movements that bring separate land masses together and introduce
> new
> competitors, predators, etc.; more subtle changes of various sorts
> which
> a highly specialized group cannot cope with. This would look like
> senescence in the fossil record, while fitting exactly into an
> evolutionary pattern.
>
> I've obviously painted with a broad brush. There are surely more
> subtle
> matters which, if we could but recognize them across strata, would
> give a
> a tighter evolutionary explanation. Then there are such matters as
> genetic drift, which do not fit into the notion of becoming better
> adapted. These are part of the total pattern. Put together (and
> since I
> am looking on from outside, I believe there must be many other
> factors
> that insiders can supply), there seems to me to be no dissonance
> between
> "senescence" and evolutionary theory.
>
> Dave>>
>
> Dave,
>
> You have described the process of extinction, not phyletic aging.
> These are
> two distinctly different processes. Aging is caused primarily be
> internal
> factors, not environmental ones, and is characterized by increasing
> disorder
> and decline in individual organisms, and in groups of them.
> Increasing
> disorder and decline can be observed at the phyletic level, that is,
> in
> taxonomic groups, as well as in individuals.
>
> Your response, Dave, illustrates what happens so often when the
> Darwinian
> paradigm is challenged. Immediately someone springs to its defense.
>
> Without, I assume, having given any serious study to the process of
> aging,
> which is extremely complex, especially when applied to phyletic
> groups, you
> have stretched the theory of evolution to encompass it, to your
> satisfaction,
> and perhaps that of others, and have thus disposed of the challenge.
>
>
> I am in the process of organizing my studies of phyletic aging, but
> ask your
> forbearance for the delay in completing it as I have a serious
> family matter
> that will require my attention for the time being. I promise, DV,
> to get
> back to this topic later.
>
> Bob
>
>
>
>
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