On Mon, 17 Aug 1998 06:17:45 -0500, Glenn R. Morton wrote:
[continued]
>GM>it is also found at the correct time for the evolution of feathers
>prior to the evolution of birds.
In fact one of the arguments against Longisquama is that it is far *too*
early, as one of Glenn's own references states:
"Ironically, if one does use Feduccia and Martin's reasoning that
Longisquama is a close bird 'ancestor' as advocated elsewhere 10, the
temporal paradox increases. Longisquama comes from rocks about 220
million years old, creating a fossil-free gap of more than 80 million years
before the appearance of Archaeopteryx Any empirical measure of
stratigraphic fits will prefer a hypothesis of maniraptoran relationships over
this one." (Norell M.A., et. al., reply to Feduccia A. & Martin L.D.,
"Theropod- bird link reconsidered," Nature, Vol. 391, 19 February 1998,
p754)
>GM>The earliest bird, Archaeopteryx is found in the Jurassic, while the
f>ossil we will discuss, Longisquama, is found in the preceding Triassic.
Yes. What Glenn fails to mention is that "the Jurassic" was 208-144 mya,
while "the...Triassic" was 245-208 mya. So Longisquama and
Archaeopteryx could be 100 myrs apart and still be in the neighbouring
geological periods. In fact, Archaeopteryx dates from ca. 140 mya and
Longisquama from ca. 220 mya, so they were nearly at the opposite ends
of th Jurassic and Triassic!
>GM>The Claim
>>
>>Young-earth Creationists often make the claim that there are no
>transitional fossils.
It's not only "Young-earth Creationists" who make that claim. Some
eminent evolutionists make it too! For example, the late Colin Patterson,
who was senior paleontologist at the British Museum of Natural History
(which has one of the world's largest collection of fossils, including
Archaeopteryx), stated "there is not one such fossil for which one could
make a watertight argument [that it was a transitional fossil]. The reason is
that statements about ancestry and descent are not applicable in the fossil
record":
"`...I fully agree with your comments on the lack of direct illustration of
evolutionary transitions in my book. If I knew of any, fossil or living, I
would certainly have included them. You suggest that an artist should be
used to visualise such transformations, but where would he get the
information from? I could not, honestly, provide it, and if I were to leave it
to artistic licence, would that not mislead the reader?'...Gould and the
American Museum people are hard to contradict when they say THERE
ARE NO TRANSITIONAL FOSSILS. As a palaeontologist myself, I am
much occupied with the philosophical problems of identifying ancestral
forms in the fossil record. You say that I should at least 'show a photo of
the fossil from which each type of organism was derived.' I will lay it on the
line-THERE IS NOT ONE SUCH FOSSIL FOR WHICH ONE COULD
MAKE A WATERTIGHT ARGUMENT. The reason is that
STATEMENTS ABOUT ANCESTRY AND DESCENT ARE NOT
APPLICABLE IN THE FOSSIL RECORD. Is Archaeopteryx the ancestor
of all birds? Perhaps yes, perhaps no: there is no way of answering the
question." (Patterson C., letter 10 April 1979, in Sunderland L.D.,
"Darwin's Enigma," 1988, p89. My emphasis.).
>GM>We will consider the history of one anti-evolutionary claim--the
>claim that there are no half-evolved feathers in the fossil record.
I would here like to make clear my Mediate Creationist position. I
personally see no reason why God could not have made the first bird from
a specially prepared line of dinosaur. The molecular biological evidence is
that the origin of feathers required "revolutions in genomic organization":
"The appearance of feathers defines the appearance of birds. A number of
changes defined, preceded or accompanied the event. The changes were
hierarchical in nature and included revolutions in genomic organization
(i.e., HOX and the feather keratin genes), protein sequence and shape, the
large scale organization of proteins into filaments, and in the geometry of
the cells and their roles in the follicle. Changes at each of these levels differ
or produced different products than found in its analog in reptiles. They are
essentially unique to birds and produced an evolutionary novelty. I used
analysis of extant structure and information on development to reconstruct
key events in the evolution of feathers. The ancestral reptilian epidermal
structure, while probably a scale or tubercles, is still unidentified. The
structural genes of feather proteins (phi-keratin) are tandem repeats
probably assembled from preexisting exons. They are unlike the alpha-
keratin of vertebrate soft epidermis. Amino-acid composition, shape, and
behavior of feather keratins are unique among vertebrates. The 3-
dimensional organization of the follicle and the developmental processes
are also unique. Although we lack a complete understanding of the
appearance and early role of feathers, they are clearly the results of novel
events." (Brush A.H., "On the origin of feathers," Journal of Evolutionary
Biology, 9, 1996, pp131-132)
which would qualify for what Geisler calls a "second-class miracle":
"[a] supernaturally guided event ... whose natural process can be described
scientifically (and perhaps even reduplicated by humanly controlled natural
means) but whose end product in the total picture is best explained by
invoking the supernatural." (Geisler N.L., "Christian Apologetics," 1976,
pp277-278)
Thus, if feathers were a supernaturally guided series of natural processes,
there *could* have been "half-evolved feathers", but because of the
rapidity of their production, and because any transitional forms may not
have had any selective advantage, it would be unlikely that they left any
trace in the fossil record.
So I do not deny that there *could* be "half-evolved feathers in the fossil
record", I just think it unlikely, so I am sceptical of claims that there are,
and test those claims vigorously.
>GM>Consider the following statements concerning transitions between
>reptilian scales and avian feathers made by various creationists. To work
>backwards in time,
>>Gish wrote (1993, p. 137):
>>
>>"If evolution has produced millions of species, including many thousands
>of different basic morphological designs, via intermediates, whereby sea
>urchins changed into fish, fins changed into legs, scales changed into
>feathers, forelimbs changed into wings, legs changed into flippers, ape-
like >skulls changed into human skulls, etc., why can't evolutionists
imagine >what the intermediates may have looked like?"
Glenn conveniently leaves out that Gish was referring to a claim by Gould
and Eldredge that "Smooth intermediates between Bauplane are almost
impossible to construct, EVEN IN THOUGHT EXPERIMENTS..."
(Gould S. J. & Eldredge N., "Punctuated Equilibria", Paleobiology 3:147,
1977, in Gish D.T., "Creation Scientists Answer Their Critics," 1993,
p136. My emphasis.)
And Glenn also conveniently leaves out that Gish then immediately after
(indeed in the same paragraph) actually gave some examples for them:
"Perhaps Gould and Eldredge have tried. They may have attempted, for
example, to imagine what viable, functional intermediates between a land
animal and a whale may have looked like. Evolutionists have suggested that
some hairy, four-legged mammal, perhaps something that may have
resembled a pig, a cow, or a buffalo (or perhaps a carnivore of some kind)
ventured into the water in search of food or sanctuary. Over eons of time,
it is imagined, the tail changed into flukes, the hind legs gradually
disappeared, the front legs changed into flippers, the nostrils gradually
migrated to the top of the head, and the skin was replaced by a heavy coat
of blubber, just to name a few of the changes required. It may be that
Gould and Eldredge tried to imagine what the intermediates looked like, in
going from a land animal to a whale, and discovered that such an attempt
was impossible." (Gish D.T., 1993, p137)
More examples of Glenn's "Christian Accountability"!
>GM>Morris and Parker preceded Gish by stating(1987, p. 11):
>>
>>"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."
That is true of Longisquama. It's claimed "featherlike scales" are 100%
scales and 0% feathers! A true "half-scales/half feathers" would be literally
that: part true reptile scale and part true bird's feather. There is no such
thing yet discovered AFAIK. Fossils are either found with 100% scales or
100% feathers:
"Once again, the existence of stratomorphic intermediate groups and
species seems to be good evidence for evolution. However, the
stratomorphic intermediate evidences are not without difficulty for
evolutionary theory. First, NONE OF THE STRATOMORPHIC
INTERMEDIATES HAVE INTERMEDIATE STRUCTURES. Although
the entire organism is intermediate in structure, it's the combination of
structures that is intermediate, NOT THE NATURE OF THE
STRUCTURES THEMSELVES. Each of these organisms appears to be a
fully functional organism full of FULLY FUNCTIONAL STRUCTURES.
Archaeopteryx, for example, is thought to be intermediate between reptiles
and birds because it has bird structures (e.g, FEATHERS) and reptile
structures (e.g., teeth, forelimb claws). Yet the teeth, the claws, the
FEATHERS and all other known structures of Archaeopteryx appear to be
FULLY FUNCTIONAL. The teeth seem fully functional as teeth, the
claws as claws, and the FEATHERS AS ANY FLIGHT FEATHERS OF
MODERN BIRDS. It is merely the combination of structures that is
intermediate, NOT THE STRUCTURES THEMSELVES." (Wise K.P.,
"The Origin of Life's Major Groups," in Moreland J.P. ed., "The Creation
Hypothesis," 1994, p227. My emphasis)
>GM>Shute citing Douglas Dewar (1961, p. 171):
>>
>>"Paleontology lends no support to the notion that evolution has occurred;
>no fossils have been found exhibiting any structure intermediate between the
>scale of a reptile and a fully formed feather, nor any displaying a fore limb
>intermediate between that of an ordinary terrestrial or aquatic animal and a
>wing. The feathers of the earliest-known fossil bearing them--
>Archaeopteryx--are as perfect as those of living birds; in the earliest- known
>fossils of pterodactyls and bats the wings are fully developed."
That statement by Dewar is still true. "no fossils *have* been found exhibiting
*any* structure intermediate between the scale of a reptile and a FULLY FORMED
feather" (emphasis mine). Longisquama's scales are 100% scales and are only
superficially like "a fully formed feather".
[continued]
Steve
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Stephen E (Steve) Jones ,--_|\ sejones@ibm.net
3 Hawker Avenue / Oz \ senojes@hotmail.com
Warwick 6024 ->*_,--\_/ Phone +61 8 9448 7439
Perth, West Australia v "Test everything." (1Thess 5:21)
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