Reflectorites
On Wed, 14 Jun 2000 01:00:59 -0700, Cliff Lundberg wrote:
...]
>SJ>These days it is recognised that, contrary to Darwin's theory, almost all
>>speciation is due to branching (i.e. cladogenesis) due to isolation and
>>genetic drift.
CL>Darwin had a clear idea of lineages radiating into niches, and adapting
>to those niches. This was the idea that he thought memorable enough
>to remember the spot in the road where it occurred to him.
Agreed. But as I responded to Susan's post of an excerpt from Darwin's
Autobiography, personally I am suspicious of this. Darwin wrote this after
he had received Wallace's manuscript. Darwin wrote voluminous notes in
his notebooks and journals, but AFAIK he did not write down in them
exactly when and where he had this `Damascus Road experience'!
>SJ>As usual, the problem is in words having multiple meanings. In this case
>>"gradual", which as a noun literally means "steps":
>>...
>>but which also, as an adjective, means: "1 : proceeding by steps or
>>degrees"; and "2 : ...changing...by fine or often imperceptible degrees":
CL>Clearly the secondary definition is the one Darwin had in mind. There
>should be no confusion about what Darwinian gradualism is. It is
>"imperceptible" change.
Agreed. And that is the mainstream Neo-Darwinist position today.
>SJ>Thus Dawkins' Neo-Darwinist idea of "gradual" is micromutations (i.e.
>>microevolution) accumulating by "fine ... imperceptible degrees" into major
>>changes (i.e. macroevolution); whereas Gould's punctuationist idea of
>>"gradual" is "proceeding by steps or degrees" some of which are *big*
>>steps (i.e. macromutations leading directly to macroevolution).
CL>I was unaware that PE theory involved macromutations. My reading of
>it is that it is about the irregular pace of evolution, the long periods of
>stasis between evolutionary stages. But when change occurs, it is through
>gradual Darwinian evolution.
Gould in his early "New and General Theory" period argued for "potential
saltatory change" and speculated that major changes (e.g. the jaws of fish)
arose in one step:
"I do not doubt the supreme importance of preadaptation, but the other
alternative, treated with caution, reluctance, disdain or even fear by the
modern synthesis, now deserves a rehearing in the light of renewed interest
in development: perhaps, in many cases, the intermediates never existed. I
do not refer to the saltational origin of entire new designs, complete in all
their complex and integrated features-a fantasy that would be totally anti-
Darwinian in denying any creativity to selection and relegating it to the role
of eliminating old models. Instead, I envisage a potential saltational origin
for the essential features of key adaptations. Why may we not imagine that
gill arch bones of an ancestral agnathan moved forward in one step to
surround the mouth and form proto-jaws? Such a change would scarcely
establish the Bauplan of the gnathostomes. So much more must be altered
in the reconstruction of agnathan design-the building of a true shoulder
girdle with bony, paired appendages, to say the least. But the discontinuous
origin of a proto-jaw might set up new regimes of development and
selection that would quickly lead to other, coordinated modifications."
(Gould S.J., "Is a new and general theory of evolution emerging?"
Paleobiology, Vol. 6, No. 1, January 1980, p.127)
But Gould, to avoid being ostracised altogether, has backpedalled ever
since!
>>CL>Macroevolutionary events are saltations, real leaps in a single generation.
>>
>>This is *one* definition of "macroevolution". But, since the Latin
>>macro="large" and micro= "small", they literally just mean large- and small-
>>scale evolution:
CL>Generally they're considered Greek words, but they are used in Latin.
>'Macro' for example, would usually be 'magna' or 'magnus' in Latin.
Thanks to Cliff for this correction. I usually check every claim I make and
I even looked up a Latin-English dictionary and found one Latin word
starting with "macro" (not "macroevolution") and in my hurry assumed
that macro must be a Latin word. But it seems it was a Greek loan word
into Latin.
CL>It's fair to say that macroevolution has not had enough support to have
>developed a standardized terminology.
According to the Webster's Dictionary I cited, "macroevolution" has been
in use since "1939". That's over 60 years. More than enough time to
develop a "standardized terminology". The problem is that evolutionary
theory so depends on shifting definitions to survive, that evolutionists
cannot resolve these definitions among themselves. The upshot is that
each evolutionist has his set of private definitions and they think they are
communicating, when really it is a `Tower of Babble'!
>>CL>Your loyalty to Darwinian gradualism ...
>SJ>Maybe Susan realises that it is only "Darwinian gradualism"
>>which can (in theory at least) reliably craft complex designs?
CL>Even irreducibly complex ones?
Darwinism simply denies there is such a thing as "irreducibly complex"
designs. They have to, because as Darwin said, Darwinian evolution
theory would then have "absolutely broken down"!
>SJ>It will be found that Cliff himself, despite all his symbiosis
>>`hand-waving', falls back on "Darwinian gradualism" when he
>>has to explain which symbiotic mergers, out of his imaginary
>>"astronomical" numbers of them, actually survived.
CL>No, that is due to natural selection; this is not a gradual mechanism
>of evolution, gradualism is not involved.
As Gould says, "natural selection" does not have to be gradual in the "2 :
...changing...by fine or often imperceptible degrees" sense, but it does have
to be gradual in the "1 : proceeding by steps or degrees" sense Cliff's
"`astronomical' numbers of them" which actually survived" shows it is still
Darwinism at crucial points.
This is what Johnson pointed out, that it is not possible to get away from
"natural selection" in *any* theory of naturalistic evolution. As soon as
design building needs to be done, the `blind watchmaker' has to be assumed
to have done it:
"When unfriendly critics are absent, Darwinists can just assume the creative
power of natural selection and employ it to explain whatever change or
lack of change has been observed. When critics appear and demand
empirical confirmation, Darwinists can avoid the test by responding that
scientists are discovering alternative mechanisms, particularly at the
molecular level, which relegate selection to a less important role. The fact
of evolution therefore remains unquestioned, even if there is a certain
amount of healthy debate about the theory. Once the critics have been
distracted, the Blind Watchmaker can reenter by the back door. Darwinists
will explain that no biologist doubts the importance of Darwinian selection,
because nothing else was available to shape the adaptive features of the
phenotypes." (Johnson P.E., "Darwin on Trial", 1993, pp.153-154).
>SJ>It is interesting to see how evolutionists use the fear of helping
>>creationists to try to keep each other in line.
CL>After all this time, anti-creationism still seems to be the major interest
>of some evolutionists.
Seeing it was *Cliff* himself who warned Susan, it seems therefore that
"anti-creationism still seems to be the major interest of" *all*
"evolutionists"!
Steve
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"Speciation is an historical process and therefore hypotheses of speciation
cannot be falsified by scientific experimentation. It is impossible to repeat a
speciation event under controlled conditions except for some unusual
modes of speciation not infrequently found in plants but very rarely in
animals. Thus, indirect evidence from the fossil record, from comparative
studies of morphology and development, DNA and proteins, from
cytogenetics and from biogeography are used to test ideas and theories
about speciation." (Knox B., Ladiges P. & Evans B., eds., "Biology",
[1994], McGraw-Hill: Sydney, Australia, 1995, reprint, p.707)
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
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