On Wed, 5 Jul 1995 22:57:28 -0400 you wrote:
SJ>ABSTRACT: This is part three of my four part response to Glenn's
whale transitional form post, pointing out problems with the
naturalistic evolutionary hypothesis, namely: 3. the difficulty of
Darwinist mechanisms of mutation and cumulative natural selection to
account for the immense changes involved in transforming a land-mammal
like a Mesonychid into a whale. It is very long and consists of a
number of long quotes. For that reason I have divided it into parts A
and B.
3. Mechanism
The real issue, is not transitional forms, but genetic mutations and
the rates they occur. Behind change in form is genetic change by
random point mutations. Dawkins points out that "the very heart of
the evolution theory, which gives it the power to dissolve
astronomical improbabilities and explain prodigies of apparent
miracle" is "slow, gradual, cumulative natural selection" (Dawkins R.,
"The Blind Watchmaker", 1991, Penguin, p318).
The reason is fundamental, as Dawkins explains:
"To 'tame' chance means to break down the very improbable into less
improbable small components arranged in series. No matter how
improbable it is that an X could have arisen from a Y in a single
step, it is always possible to conceive of a series of infinitesimally
graded intermediates between them. However improbable a large-scale
change may be, smaller changes are less improbable. And provided we
postulate a sufficiently large series of sufficiently finely graded
intermediates, we shall be able to derive anything from anything else,
without invoking astronomical improbabilities. We are allowed to do
this only if there has been sufficient time to fit all the
intermediates in. And also only if there is a mechanism for guiding
each step in some particular direction, otherwise the sequence of
steps will career off in an endless random walk." (Dawkins, p317).
There is a tendency to try to get around the restrictive role of
Neo-Darwinist gradualism by single-step, large-scale changes, ie.
macro-mutations. But Dawkins rejects this as a general principle:
"...macromutations do happen. But do they play a role in evolution?
People called saltationists believe that macromutations are a means by
which major jumps in evolution could take place in a single
gcncration. Richard Goldschmidt...was a true saltationist. If
saltationism were true, apparent 'gaps' in the fossil record needn't
be gaps at all..There are very good reasons for rejecting all such
saltationist theories of evolution. One rather boring reason is that
if a new species really did arise in a single mutational step, members
of the new species might have a hard time finding mates..." (Dawkins,
p231)
Dawkins also rejects punctuated equilibria as an explanation of
major evolutionary change, except in special cases:
"If there are versions of the evolution theory that deny slow
gradualism, and deny the central role of natural selection, they may
be true in particular cases. But they cannot be the whole
truth..." (Dawkins, p318).
Denton agrees that punctuated equilibria, with its emphasis on rapid
speciation in small, isolated populations, is inadequate to explain
the major gaps in the fossil record:
"While Eldredge and Gould's model is a perfectly reasonable
explanation of the gaps between species (and, in my view, correct) it
is doubtful if it can be extended to explain the larger systematic
gaps. The gaps which separate species: dog/fox, rat/mouse etc are
utterly trivial compared with, say, that between a primitive
terrestrial mammal and a whale or a primitive terrestrial reptile and
an Ichthyosaur; and even these relatively major discontinuities are
trivial alongside those which divide major phyla such as molluscs and
arthropods. Such major discontinuities simply could not, unless we
are to believe in miracles, have been crossed in geologically short
periods of time through one or two transitional species occupying
restricted geographical areas" (Denton M., "Evolution: A Theory in
Crisis",1985, Burnett Books, p193)
Therefore the change from a mesonychid to a whale can only occur in
Darwinist evolution, by "slow, gradual, cumulative natural selection":
Denton points out some the issues involved in the transition from land
mammal to whale:
"Between sea otter and seal and between seal and whale there are
enormous discontinuities unbridged by any known or extinct form...D.
Dewar, a leading anti-evolutionist in the 1930s, challenged his
zoological colleagues to provide detailed blueprints of intermediate
forms (Dewar D., "More Difficulties of the Evolution Theory", Thynne &
Co., London, pp23-4):
`...Let us notice what would be involved in the conversion of a land
quadruped into, first a seal-like creature and then into a whale. The
land animal would, while on land, have to cease using its hind legs
for locomotion and to keep them permanently stretched out backwards on
either side of the tail and to drag itself about by using its
fore-legs. During its excursions in the water, it must have retained
the hind legs in their rigid position and swim by moving them and the
tail from side to side As a result of this act of self-denial we must
assume that the hind legs eventually became pinned to the tail by the
growth membrane Thus the hind part of the body would have become like
that of a seal. Having reached this stage, the creature in
anticipation of a time when it will give birth to its young under
water, gradually develops apparatus by means of which the milk is
forced into the mouth of the young one, and meanwhile a cap has to be
formed round the nipple into which the snout of the young one fits
tightly, the epiglottis and laryngeal cartilage become prolonged
downwards so as tightly to embrace this tube, in order that the adult
will be able to breath while taking water into the mouth and the young
while taking in milk These changes must be effected completely before
the calf can be born under water. Be it noted that there is no stage
intermediate between being born and suckled under water and being born
and suckled in the air. At the same time various other anatomical
changes have to take place, the most important of which is the
complete transformation of the tail region. The hind part of the body
must have begun to twist on the fore part, and this twisting must have
continued until the sideways movement of the tail developed into an
up-and-down movement. While this twisting went on the hind limbs and
pelvis must have diminished in size, until the latter ceased to exist
as external limbs in all, and completely disappeared in most, whales.'
(Dewar D., "More Difficulties of the Evolution Theory", Thynne & Co.,
London, pp23-24, in Denton M., "Evolution: A Theory in Crisis", 1985,
Burnett Books, pp217-218)
If evolutionists wish to maintain that a mesonchynid was the ancestor
of whales, by a naturalistic mechanisms of genetic mutation and
cumulative natural selection, then they need to explain to sceptics
how those mechanisms alone could produce such major changes. Denton:
"By its very nature, evolution cannot be substantiated in the way that
is usual in science by experiment and direct observation. Neither
Darwin nor any subsequent biologist has ever witnessed the evolution
of one new species as it actually occurs. Outside of direct
observation the only means of providing decisive evidence for
evolution is in the demonstration of unambiguous sequential
arrangements in nature.
To show that any two species of organism are related in an
evolutionary sense, to show for example that one species A, is
ancestral to B, ie A->B or that both species have descended from a
common ancestral source, ie A<->B, it is necessary to satisfy one of
the following conditions. Either one, to find a 'perfect' sequence of
fully functional intermediate forms I1, I2, I3 leading unambiguously
from one species to another, ie A->I1->I2->I3->B, or...two, to
reconstruct hypothetically in great detail the exact sequence of
events which led from A to B or from a common ancestor to A and B,
including thoroughly convincing reconstructions of intermediate forms
and a rigorous and detailed explanation of how and why each stage in
the transformation came about."
(Denton M., "Evolution: A Theory in Crisis",1985, Burnett Books, p56)
Continued #3B. Mechanism
God bless.
Stephen