Reflectorites
On Wed, 20 Sep 2000 16:39:30 -0500, Susan Brassfield Cogan wrote:
[...]
>BV>It is possible that whales evolved from some wolf-like creature. What is
>>being questioned is whether it happened because of "chance variation and
>>natural selection".
SB>since we can watch variation (whether "chance" or not) and natural
>selection happen every day ...
Compare this with:
--------------------------------------------------------------------
On Mon, 18 Sep 2000 23:17:43 -0500 (CDT), Wesley R. Elsberry wrote
re: Examples of natural selection generating CSI:
[...]
WE>Natural selection, though, is notoriously difficult to
>empirically isolate as a mechanism of action. The level of
>evidence needed to both implicate natural selection and to
>exclude genetic drift is high. [...]
--------------------------------------------------------------------
So when asked to give hard evidence of random mutation and natural
selection accomplishing anything *today*, Darwinists either downplay
RM&NS and talk of other mechanisms, or they present evidence of
something *trivial* (like fluctuating colours in moths or length of finches'
beaks), and even then there is some doubt that RM&NS was responsible.
But then as soon as they need to explain a case of new design in the
*distant past*, out they trot RM&NS as the explanation, in this case
transforming a small land mammal into a whale in only 5-10 million years!
Johnson explains the basic manoeuvre:
"Manipulation of the terminology also allows natural selection to
appear and disappear on command. 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)
BTW neither Johnson nor I claim the Darwinists are dishonest in this. They
appear to *really* believe that what they are presenting is true, and it is the
critics who are "ignorant, stupid or insane ... or wicked" (Dawkins, 1989)!
Here are some of the problems for RM&NS in the land mammal-whale
transition (which I accept probably happened BTW but not by RM&NS):
1. the changes required:
"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 than 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 swum 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 be came pinned
to the tail by the growth of membrane. Thus the hind part of the
body would have become likes 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 upwards to form a cone-shaped tube,
and the soft palate becomes prolonged downwards so as tightly to
embrace this tube, in order that the adult will be able to breathe
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 nave 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," 1938, p.23)
Maybe this is an example of what Gould & Eldredge had in mind when
they wrote:
"At the higher level of evolutionary transition between basic
morphological designs, gradualism has always been in trouble,
though it remains the "official" position of most Western
evolutionists. Smooth intermediates between Bauplane are almost
impossible to construct, even in thought experiments." (Gould S.J.
& Eldredge N., "Punctuated equilibria: the tempo and mode of
evolution reconsidered," Paleobiology, 1977, Vol. 3, pp.115-147,
p.147)
2. the timeframe in the fossil record (i.e. ~10 million years):
"Today, our more detailed knowledge of fossil mammals lays
another knotty problem at the feet of gradualism. Given a simple
little rondentlike animal as a starting point, what does it mean to
form a bat in less than ten million years, or a whale in little more
time? We can approach this question by measuring how long
species of mammals have persisted in geological time. The results
are striking; we can now show that fossil mammal populations
assigned to a particular Cenozoic lineage typically span the better
part of a million years without displaying sufficient net change to be
recognized as a new species. The preceding observations permit us
to engage in another thought experiment. Let us suppose that we
wish, hypothetically, to form a bat or a whale without invoking
change by rapid branching. In other words, we want to see what
happens when we restrict evolution to the process of gradual
transformation of established species. If an average chronospecies
lasts nearly a million years, or even longer, and we have at our
disposal only ten million years, then we have only ten or fifteen
chronospecies to align, end-to-end, to form a continuous lineage
connecting our primitive little mammal with a bat or a whale. This
is clearly preposterous. Chronospecies, by definition, grade into
each other, and each one encompasses very little change. A chain of
ten or fifteen of these might move us from one small rodentlike
form to a slightly different one, perhaps representing a new genus,
but not to a bat or a whale!" (Stanley S.M., "The New Evolutionary
Timetable," 1981, pp.93-94)
3. the driver in RM&NS is supposed to be competition, but competition
would be *reduced* in a vast new ecological niche like an ocean.
4. it is numbers of *offspring* which is important to RM&NS, but larger
mammals have long comparatively gestation and generation times and small
numbers of offspring:
"The presenters could not have picked any more vulnerable
"evidences" than the whale species. The whale's capacity for natural
process change is severely limited by ... 2) long generation spans
(the time between birth and the ability to give birth); 3) low number
of progeny produced per adult; ... these factors severely limit a
species' capacity to change, or even to adapt to change, through
mutations and natural selection." (Ross H.N., "Creation on the `Firing
Line'", Facts & Faith, First Quarter 1998.
http://www.reasons.org/resources/FAF/98q1faf/98q1aisi.html)
5. vast numbers of intermediates in the fossil record (not just a handful)
are needed to establish RM&NS:
"Darwin's insistence that gradual evolution by natural selection
would require inconceivable numbers of transitional forms may
have been something of an exaggeration but it is hard to escape
concluding that in some cases he may not have been so far from the
mark. Take the case of the gap between modern whales and land
mammals. All known aquatic or semi-aquatic mammals such as
seals, sea cows (sirenians) or otters are specialized representatives
of distinct orders and none can possibly be ancestral to the present-
day whales. To bridge the gap we are forced therefore to postulate
a large number of entirely extinct hypothetical species starting from
a small, relatively unspecialized land mammal like a shrew and
leading successfully through an otter-like stage, seal-like stage,
sirenian-like stage and finally to a putative organism which could
serve as the ancestor of the modern whales. Even from the
hypothetical whale ancestor stage we need to postulate many
hypothetical primitive whales to bridge the not inconsiderable gaps
which separate the modern filter feeders (the baleen whales) and the
toothed whales. Moreover, it is impossible to accept that such a
hypothetical sequence of species which led directly from the
unspecialized terrestrial ancestral form gave rise to no collateral
branches. Such an assumption would be purely ad hoc, and would
also be tantamount to postulating an external unknown directive
influence in evolution which would be quite foreign to the spirit of
Darwinian theory and defeat its major purpose of attempting to
provide a natural explanation for evolution. Rather, we must
suppose the existence of innumerable collateral branches leading to
many unknown types. This was clearly Darwin's view and it implies
that the total number of species which must have existed between
the discontinuities must have been much greater than the number of
species on the shortest direct evolutionary pathway. In the diagram
opposite, which shows a hypothetical lineage leading from a land
mammal to a whale, while there are ten hypothetical species on the
direct path, there are an additional fifty-three hypothetical species
on collateral branches. Considering how trivial the differences in
morphology usually are between well-defined species today, such as
rat-mouse, fox-dog, and taking into account all the modifications
necessary to convert a land mammal into a whale - forelimb
modifications, the evolution of tail flukes, the streamlining,
reduction of hindlimbs, modifications of skull to bring nostrils to
the top of head, modification of trachea, modifications of behaviour
patterns, specialized nipples so that the young could feed
underwater (a complete list would be enormous) one is inclined to
think in terms of possibly hundreds, even thousands, of transitional
species on the most direct path between a hypothetical land
ancestor and the common ancestor of modern whales." (Denton
M.J., "Evolution: A Theory in Crisis," 1985, pp.172,174)
But:
"To demonstrate that the great divisions of nature were really
bridged by transitional forms in the past, it is not sufficient to find in
the fossil record one or two types of organisms of doubtful affinity
which might be placed on skeletal grounds in a relatively
intermediate position between other groups. ... It is clear that there
are formidable problems in interpreting evidence for continuity on
the basis of skeletal remains. Consequently if the fossil record is to
provide any grounds for believing that the great divisions of nature
are not the unbridgeable discontinuities postulated by Cuvier, it is
not sufficient that two groups merely approach one another closely
in terms of their skeletal morphology. The very least required
would be an unambiguous continuum of transitional species
exhibiting a perfect gradation of skeletal form leading unarguably
from one type to another. But the fact is that, as Stanley put it:
`The known fossil record fails to document a single example of
phyletic (gradual) evolution accomplishing a major morphologic
transition and hence offers no evidence that the gradualistic model
can be valid.' (Stanley, S.M., "Macroevolution," 1979, p.39)
(Denton, 1985, pp.177,182).
Note that the evidence of a small number of intermediates (while it disconfirms
YEC) actually supports what Denton calls "an external unknown directive influence
in evolution", i.e. an Intelligent Designer, not `blind watchmaker' RM&NS!
Steve
--------------------------------------------------------------------------
"Few contemporary paleontologists would deny that natural selection
controls the direction of evolution, but many would seek additional factors
to account for the rapid evolution that characterizes the early
diversification and radiation of groups and the early stages in the
elaboration of major new structures. The great longevity of many groups
and the minor evolutionary changes they exhibited pose another problem."
(Carroll R.L., "Vertebrate Paleontology and Evolution," W.H. Freeman &
Co: New York NY, 1988, pp.4-5)
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
--------------------------------------------------------------------------
This archive was generated by hypermail 2b29 : Sun Sep 24 2000 - 18:20:56 EDT