On Sat, 04 Apr 1998 14:09:16 -0600, Glenn Morton wrote:
GM>I just ran into the following data which contradicts one of the
>favorite anti-evolutionary claims. The claim is as follows, Morris
>and Parker state,
>
>"There are no true transitional forms (that is, in the sense of
>forms containing incipient, developing or transitional structures
>- such as half- scales/half feathers, or half-legs/ half wings)
>anywhere among all the billions of known fossil forms." ~Henry M.
>Morris and Gary E. Parker, What is Creation Science?, (El Cajon:
>Master Books, 1987), p. 11
That is still the case. What do you think all the flap (pun intended!)
is all about regarding the recent claims for feathers on dinosaurs in
China?
GM>Feduccia and Wild relate:
>
>"Megalancosaurus, in combination with Longisquama, a Lower
>Triassic thecodont with featherlike scales and furcula, render
>this group (basal archosaurs, including thecodonts) the most
>liekly candidate for proximity to avian ancestry."~A. Feduccia
>and R. Wild, "Birdlike Characters in the Triassic Archosaur
>Megalancosaurus," Naturwissenschaften, 80(1993):564-566
>
>It would appear that the antievolutionary claim is not verified by
>observational data.
This is dated *1993* and is in a non-English speaking journal at that.
What exactly are "featherlike scales" and "Birdlike Characters"? Do
you seriously think that if *real* half-scales/half-feathers had been
found *six years ago* it would not have been trumpeted from the
evolutionary rooftops and republished in SCIENCE and NATURE?
Prominent avian researcher A.H. Brush points out that at the
molecular level there is *no* connection between reptile scales and
bird feathers:
"It has been a truism for most of this century that feathers are related
to reptilian scales. Various authors have argued that feathers are
derived directly from reptilian scales or possibly tubercles (Thulborn,
1987). It almost goes without saying that the scales on birds must
also be homologous to reptilian scales. If this homology exists then
one would expect similarities at all levels of organization...I will
provide arguments to show that reptilian scales and feathers are
related only by the fact that their origin is in epidermal tissue. Every
feature from gene structure and organization, to development,
morphogenesis and tissue organization is different. I believe that
while there is phenotypic similarity in some scales, that feathers are
unique to birds and deserve consideration as an evolutionary
novelty." (Brush A.H., "On the origin of feathers," Journal of
Evolutionary Biology, 9, 1996, p132)
Gish points out:
"Scales are flat horny plates; feathers are very complex in structure,
consisting of a central shaft from which radiate barbs and barbules.
Barbules are equipped with tiny hooks which lock onto the barbs and
bind the feather surface into a flat, strong, flexible vane. Feathers and
scales arise from different layers of the skin. Furthermore, the
development of a feather is extremely complex, and fundamentally
different from that of a scale. Feathers, as do hairs but unlike scales
develop from follicles. A hair, however, is a much simpler structure
than a feather. The developing feather is protected by a horny sheath
and forms around a bloody, conical, inductive dermal core. Not only
is the developing feather sandwiched between the sheath and dermal
core, it is complex in structure. Development of the cells that will
become the mature feather involves complex processed cells migrate
and split apart in highly specific patterns to form the complex
arrangement of barbs and barbules." (Gish D.T., "Evolution: The
Fossils Still Say NO!," 1995, p136)
Gish continues:
"Philip Regal attempts to imagine how feathers may halve developed
from scales. (Regal P.J., The Quarterly Review of Biology, Vol.
50, 1975, p35) Regal presents a series of hypothetical events
whereby the elongation of body scales on reptiles, as an adaptive
response to excessive solar heat, eventually produced feathers.
What we are left to believe is that a series of genetic mistakes, or
mutations, just happened somehow to result in a sequence of
incredible events that not only converted a simple horny plate into
the tremendously complex and marvelously engineered structure of a
feather, but completely reorganized the simple method of development
of a scale into the highly complex proceeds necessary to produce a
feather... P. F. A Anderson has also suggested a scenario for the
origin of feathers from reptilian scales. He is frank enough to
admit, however, that: `I emphasize that this model only attempts to
explain how an archosaurian scale might have given rise to a
proto-feather. The end product as shown in figure 1d resembles a
feather in the usual sense of the word only in that it is a highly
specialized keratinous integumentary appendage. We cannot as yet
offer any plausible explanation for the origin of the unique shaft;
barbs, and barbules without which modern feathers would have neither
aerodynamic nor insulatory function.' (Maderson P.F.A., "The
American Naturalist", Vol. 146, 1972, p427). (Gish D.T., 1995,
p136)
I personally have no problem with the first bird(s) being mediately
created from a reptilian common ancestor. But I doubt that it was
by a fully naturalistic, evolutionary process. I fully expect that
when all the facts are in, the origin of feathers will be more
evidence for *creation* not evolution.
Steve
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Stephen E (Steve) Jones ,--_|\ sejones@ibm.net
3 Hawker Avenue / Oz \ Steve.Jones@health.wa.gov.au
Warwick 6024 ->*_,--\_/ Phone +61 8 9448 7439
Perth, West Australia v "Test everything." (1Thess 5:21)
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