Re: ORIGINS: Phyletic Change

Paul Arveson (arveson@oasys.dt.navy.mil)
Mon, 16 Sep 96 09:46:57 EDT

Bob DeHaan wrote:

>Ernst Mayr criticized Goldschmidt for holding that, "logic as well as
>historical fact tell us that the big categories existed first, and then in
>time they split in the form of the genealogical tree into lower and still
>lower categories" (Goldschmidt, 1952. 91-2). Mayr said "With this
>interpretation Goldschmidt has fallen into the error of considering these
>categories something natural rather than (particularly in the crucial area of
>branching) a man-made artifact. Our recognition of a higher category and
>its designation, delimitation, and placement in a hierarchy have a large
>arbitrary component" (Mayr, 1963 pp. 600-1).
>
>These criticisms are automatic, defensive reflexes. Rather than reexamining
>their paradigm in the light of the objective data, these authors attack the
>data and the straightforward interpretation of it in order to protect the
>evolutionary paradigm. The stakes are high. If the top-down view prevails,
>the Darwinian paradigm will suffer irreparable loss.

Bob, I know you want to stop this thread, but I wonder if first you or Keith or
someone will please explain why it would do irreparable loss to the Darwinian
paradigm.

I note that nowhere in your subsequent description do you refer to genetic
changes. In our discussion about the bias caused by lack of soft-bodied forms
in the fossil record, I note the obvious fact that perhaps the greatest bias is
that DNA is not preserved (except perhaps a little in amber, etc). Therefore,
paleontology is doomed to being a morphological science rather than a more
rigorous and objective genomic science. Perhaps a lot of the controversies
about evolution will never be settled, but we do know based on existing, living
organisms that genetic functions are in some cases hierarchical. That is, some
genes don't just make a protein, but they control the whole manner in which
things get expressed. What happens if mutations occur in these control genes?
There are introns and exons of various lengths, as well as transposons and
repeating sequences that are dispersed throughout the genome. These facts at
least open the possibility that change may occur in large leaps as well as small
ones. I don't see how any of this is inconsistent with the fundamental
paradigm.

Paul Arveson, Research Physicist
Code 724, NSWC, Bethesda, MD 20084
73367.1236@compuserve.com arveson@oasys.dt.navy.mil
(301) 227-3831 (W) (301) 227-1914 (FAX) (301) 816-9459 (H)