On Mon, 25 Mar 1996 08:12:10 -0800 you wrote:
AC>Guilbert not only doesn't know the fossil record, he also doesn't
>contribute anything to our understanding by his proposals. To say
>that the presence of developmental pathways common in many organisms
>can be used as an explanation for evolutionary process ignores that
>the same explanation also applies to creation by a wise Creator.
>What great wisdom does Guilbert's proposal supply? All of these
>mechanisms were already present in the first metazoan organisms found
>as fossils. This still begs the question as to the origin or Origin
>of the mechanisms. Let the question reside there. Clearly his
>proposal supplies no information whatsoever about origin of the
>mechanisms, which is the only information of interest to this group
>given that the presence of the mechanism can be accommodated by
>either model.
Indeed. While I haven't yet read Gilbert, and must therefore rely on
(shudder! *secondary* sources <g>), I find it interesting
that Darwinists are already claiming this as "evolution". I haven't
had a chance to read Gilbert yet, so what I say is only from (shock!
horror!! secondary sources <g>) but even so, it sounds nothing like
"evolution" to me. Johnson points out that this evidence from
developmental biology actually undermines the Darwinian claim that
homology is the result of common ancestry:
"Common ancestry, although initially appealing as a hypothesis, is not
the true explanation for the pattern of classification (at least at
higher taxonomic levels)....The evidence from developmental biology,
supposedly a major support for the common ancestry thesis, actually
undermines it." (Johnson P.E., "Reason in the Balance",
InterVarsity Press: Downers Grove Ill., 1995, p213-214)
This is because body plans are the result of changes in Hox genes, not
in the accumulation of favourable genetic changes in other parts of
the organism's genome:
"One of the most profound ideas to emerge from developmental biology
labs in recent years is that the body plans of all animals, from fruit
flies to elephants, are controlled by the same kinds of genes.
Instead of inventing a new set of body plan genes for each new type of
animal, it seems that natural selection has simply tinkered with an
old one, a set known as Hox genes. When the first multicellular
animals evolved some 700 million years ago, biologists believe that
their body plans were largely the work of a primitive set of Hox
genes. They also believe that descendants of these genes have been
sculpting the body plans of animals ever since. The evolution of fish
into amphibians and amphibians into reptiles and so on must have
involved many genetic changes. But researchers like Bieberich believe
that elaborations of the ancestral animal body plan-involving
step-by-step mutations and duplications of Hox genes-were central to
these transformations." (Day S., "Invasion of the shapechangers", New
Scientist, 28 October 1995, p31)
The point is that Neo-Darwinism claims that there is no way that
"natural selection" can have "simply tinkered with...Hox genes."
Natural selection can only "see" *bodies* not genes:
"No matter how much power Dawkins wishes to assign to genes,
there is one thing that he cannot give them-direct visibility to
natural selection. Selection simply cannot see genes and pick among
them directly. It must use bodies as an intermediary. A gene is a
bit of DNA hidden within a cell. Selection views bodies. It favors
some bodies because they are stronger, better insulated, earlier in
their sexual maturation, fiercer in combat, or more beautiful to
behold." (Gould S.J., "The Panda's Thumb", Penguin: London, 1980,
p76).
Only an intelligent being (like a developmental biologist or a God)
can "tinker" with *genes*. Johnson says:
"Suppose that, following a massive research program, scientists
succeed in altering the genetic program of a fish embryo so that it
develops as an amphibian. Would this hypothetical triumph of genetic
engineering confirm that amphibians actually evolved, or at least
could have evolved, in similar fashion? No it wouldn't, because Gould
and the others who postulate developmental macromutations are talking
about random changes, not changes elaborately planned by human (or
divine) intelligence A random change in the program governing my word
processor could easily transform this chapter into unintelligible
gibberish, but it would not translate the chapter into a foreign
language, or produce a coherent chapter about something else. What
the proponents of developmental macromutations need to establish is
not merely that there is an alterable genetic program governing
development, but that important evolutionary innovations can be
produced by random changes in the genetic instructions." (Johnson
P.E., "Darwin on Trial", InterVarsity Press: Downers Grove: Ill.,,
Second Edition, 1993 pp42-43)
Indeed, Hox genes are so complex that *only* God could "tinker" with
them! Even Dawkins doubts that scientists will ever know how to
"tinker' with genes:
"If only we knew which genes to tinker with, which bits of chromosome
to duplicate, invert or delete. I doubt if we shall ever know enough
to do it, but these dear dead creatures are lurking there forever in
their private comers of that huge genetic hypervolume, waiting to be
found if we but had the knowledge to navigate the right course through
the maze." (Dawkins R., "The Blind Watchmaker", Penguin: London,
1991, p73)
This is particularly the case with Hox genes:
"The drawback for scientists is that nature's shrewd economy conceals
enormous complexity. Researchers are finding evidence that the Hox
genes and the non-Hox homeobox genes are not independent agents but
members of vast genetic networks that connect hundreds, perhaps
thousands, of other genes. Change one component, and myriad others
will change as well-and not necessarily for the better. Thus dreams
of tinkering with nature's toolbox to bring to life what scientists
call a "hopeful monster"-such as a fish with feet-are likely to remain
elusive. Scientists, as Duboule observes, are still far from
reproducing in a laboratory the biochemical artistry that nature has
taken millions of years to accomplish." (J. Madeleine Nash, Chicago,
"Where Do Toes Come From?", TIME, August 7,1995, p69)
If this turms out to be true, then it will be the *death knell* of
blind watchmaker Darwinism, and the greatest confirmation of Creation
since the Big Bang! But no doubt Darwinism will, like the "beast" in
Revelation 13:3, who suffered "a fatal wound', but later "the fatal
wound had been healed", accommodate this new discovery, and proclaim
that it is still "evolution"! :-) This is because of the priority of
the Darwinian paradigm. Again Johnson:
'The early developmental differences in vertebrates that precede the
pharyngula stage (which is usually employed to illustrate embryonic
similarities) are described in Scott F. Gilbert, Developmental Biology
(3rd ed., Sinauer Associates, 1991), pp. 75-154, 840. ...I should
note that none of the cited embryologists considers the anomalies
arising from embryology to contradict the Darwinian paradigm. What
needs to be kept in mind, however, is that most contemporary
biologists, including embryologists, do not consider descent with
modification (common ancestry) as a theory that needs to be proved.
It would be more accurate to say that common ancestry has become
axiomatic in biology. Features like the pentadactyl limb in
vertebrates are so generally accepted as homologous that their status
is not threatened when it turns out that they arise in different
classes via differing developmental patterns. As Thomas Kuhn tells us
(see Chapter Nine), anomalies in themselves never falsify an
entrenched paradigm, at least until a more satisfactory explanation is
found for them." (Johnson P.E., "Darwin on Trial", InterVarsity
Press: Downers Grove Ill., Second Edition, 1993, p189).
and
"Common ancestry, although initially appealing as a hypothesis, is not
the true explanation for the pattern of classification (at least at
higher taxonomic levels)....The evidence from developmental biology,
supposedly a major support for the common ancestry thesis, actually
undermines it." (Johnson P.E., "Reason in the Balance",
InterVarsity Press: Downers Grove Ill., 1995, p213-214).
God bless.
Steve
----------------------------------------------------------------
| Stephen Jones ,--_|\ sjones@iinet.net.au |
| 3 Hawker Ave / Oz \ http://www.iinet.net.au/~sjones/ |
| Warwick 6024 ->*_,--\_/ phone +61 9 448 7439. (These are |
| Perth, Australia v my opinions, not my employer's) |
----------------------------------------------------------------