In a message dated 7/21/2000 4:38:15 PM, gmurphy@raex.com writes:
<<
1) I note the Howard's caveat about the term "creative roles" but the
same
warning could be made about _any_ natural processes with which God works. >>
Granted. Delete "creative roles" and substitute, "above the species level."
Or if you will, at the higher taxonomic level of Orders, Classes and Phyla.
<<2) Second, It seems to me that you're confusing a couple of issues & in
fact
get things backward when you say "I would be happy to take macroevolution
seriously if there were empirical evidence that natural selection played a
significant *creative* role in it." That's like saying somebody in 1700
saying "I'd be happy to believe that the planets move around the sun on
elliptical orbits if there were empirical evidence for Newton's law of
gravitation." >>
George:
But almost 140 years have elapsed since Darwin's *Origin* was published. The
scientific resources available to research the role of natural selection at
the higher taxonomic levels are enormous. How much more time is needed?
<<Surely a person may be convinced by fossil evidence, biochemical and
anatomical similarities &c that macroevolution has taken place without making
any commitment at all as to its mechanism.>>
Let me quote from an "Open Letter to Paul Gross" by Jay W. Richards:
"Doubts about the efficacy of the mechanisms of microevolution for
macroevolutionary change are widespread within evolutionary biology--so
widespread, indeed, that researchers often refer to the issue by a kind of
shorthand, i.e., as the “micro-macro” controversy. The University of
Wisconsin developmental biologist Sean Carroll, for instance, writing last
month in Cell (9 June 2000, volume 101:577-580), noted “the long-standing
question of the sufficiency of evolutionary mechanisms observed at or below
the species level (‘microevolution’) to account for the larger-scale patterns
of morphological evolution (‘macroevolution’)” (p. 577) and “One of the
longest running debates in evolutionary biology concerns the sufficiency
of processes observed within populations and species for explaining
macroevolution” (p. 579).
(snip)
"The paleontologist Robert Carroll of the Department of Biology at McGill
University, for instance, argued recently in thejournal Trends in Ecology and
Evolution that “the most striking features of large-scale evolution are the
extremely rapid divergence of lineages near the time of their origin,
followed by long periods in which basic body plans and ways of life are
retained. What is missing are the many intermediate forms hypothesized by
Darwin, and the continual divergence of major lineages into the morphospace
between distinct adaptive types . . . . The extreme speed of anatomical
change and adaptive radiation during this brief time requires explanations
that go beyond those proposed for evolution of species within the current
biota” (“Towards a new evolutionary synthesis,” TREE, volume
15:27-32; p. 27).
Arguments such as Carroll’s fill the current biological literature. They
are even more widespread outside the English-speaking world."
I simply maintain that Darwinian natural selection is not competent to
account for what is called macroevolution, what I prefer to call the
formation of morphologies at the higher taxonomic levels.
<<3) "I am not a paleontologist or the son of a paleontologist", to
paraphrase
last Sunday's OT lesson. But it seems to me that the sentence you quote from
Young is not nearly so "telling" if your commentary is removed.>>
Then be so kind as to accept my commentary, which was and is: "The body
plans of organisms are generally not adaptive. They need NS. The
"significant role of natural selection" in the formation of the body plans of
phyletic lineages in the Cambrian, is to enhance the adaptations of organisms
to their surroundings with their respective Bauplans, using contemporary
'short-term-evolution' studies as the best evidence we have of the role of
NS."
<<4) Natural selection in an important sense is simply negative: there
aren't
enough resources &c for all organisms to survive so a lot will die (Malthus'
influence
on both Darwin & Wallace), & the ones with variations which best enable them
to survive
in the environment of the moment will be most likely to survive & have
offspring.
Natural selection itself says nothing about the mechanisms which may bring
about the
necessary genetic variations, & it may well be that we need some new theories
to explain
them. It is this negative aspect of natural selection - the fact that
privation, death,
& extinction make room for development of new species (however that happens)
- on which
I've concentrated theologically, & to which I was trying to call attention
earlier in
this discussion. The point is certainly not that natural selection is the
survival of
"the strong" or that it's a kind of genetic Lamarckianism, as was being
argued here
previously.
Shalom,
George >>
OK. We are together as long as you are not arguing for a long-term, positive
role for NS. But I am not sure that is the case.
Peace,
Bob
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