Re: half-evolved feathers

Stephen Jones (sejones@ibm.net)
Tue, 05 May 98 22:33:10 +0800

Glenn

On Sun, 26 Apr 1998 21:44:52 -0500, Glenn R. Morton wrote:

SJ>...I accept fully that...Longisquama insignis...was found in
>>1972*...My point is that it was...virtually ignored for 20
>>years...And for the last five years it has been virtually ignored
>>since.
>
>>*Actually it was first described in *1970* so it was probably found
>>even before then:.."These authors point to small Triassic basal
>>archosaurs such as Longisquama (Sharov 1970..." (Feduccia, 1996...

>>GM>And it was mentioned, as I said, a few weeks back in Nature. Two
>>guys accept it two guys didn't.

[...]

GM>Well a few days ago I did a lit search on longisquamis. It was
>first put in English in 1970 A. G. Sharov, "An un usual reptile
>from the Lower Triassic of Fergana, Paleontological Journal
>4:1:112-116
>
>A. De ricqles, "Les Premiers Vertebres volants, La Recherche
>6:58:608-617 (in french)
>
>H. Haubold E. buffetaut, "Une nouvelle interpretation de Longisquama
>insignis reptile enigmatique du Trias superieur d'Asie centrale," Comptes
>Rendus srie 2 305:1:65-70
>
>Omni, 16:9 p. 34 "the birds first? A theory to fit the facts.

I note that you don't mention the *dates* of these last three.

GM>and finally the reason it has been ignored is that most
>paleontologists believe that birds came from theropods Feduccia and
>Martin believe they came from the thecodonts (which is what
>Longisquama is). r. L. Disilvestro, "In quest of the origin of
>birds", Bioscience 47:8:481

No date here either.

>SJ>It is often several months before NATURE is received here in the
>>Antipodes. I would therefore appreciate you posting exact
>>references, and even a quote, please. Thanks.

GM>**** need to do***

???

>SJ>I did not deny that "it is accessible to an english speaking
>>individual". My point was that it did not feature in a mainstream
>>"English speaking journal" like SCIENCE or NATURE.

>>>SJ>You just ignore my main point: "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?"

GM>Believe it or not Stephen, Science and Nature are not the premier
>paleontological journals. If you want to know paleontology, or claim to
>have researched paleontology as many apologists want their readers to
>believe, very little of it will appear in the pages of SCIENCE and NATURE.

No doubt. But "Science and Nature" are "the premier" *science*
"journals" and they cover *all* the major paleontological issues, eg.
the recent theropods with claimed proto-feathers and early birds in
China.

GM>That is my point. Gish didn't spend much time in the journals.

If Science and Nature didn't think it worth publishing anything much
about Longisquama, then I can't see why "Gish" would. But in any
event, Gish *did* mention Maderson's article, as I posted previously:

"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.' 85

85 P.F.A Maderson, The American Naturalist 146:427 (1972).

(Gish D.T., "Evolution: The Fossils Still Say NO!," Institute for
Creation Research: El Cajon CA, 1995, p136)

>>GM>You forget Maderson.

>SJ>I don't "forget Maderson". Even he sounds tentative about it:
>>the title of his 1972 article was "On How an Archosaurian Scale
>>MIGHT have Given Rise to an Avian Feather" (my emphasis).

GM>You are a very literal person. Of course it is might. No one was
>there. Having read the article the author was proposing that it DID
>happen that way but of course he can't prove it so he uses the word
>MIGHT.

It's got nothing to do with me being "a very literal person". I
quoted what the title of Maderson article *actually said* and I have
even quoted an excerpt from it, both of which sound tentative.

>>GM>That is my point, the scales of Longisquama do resemble feathers.
>>>Thank you for agreeing with my point, finally.

>SJ>That wasn't your "point" at all. Your "point" was that
>>Longisquama was a "true transitional form...(that is, in the sense
>>of...containing incipient, developing or transitional structures-
>>such as half- scales/half feathers...":

>Actually unless you can mind read I don't know how you can know that. The
>resemblance to feathers is arguable a half feather. Many paleontologists
>beleive that dinosaurs, other than those related to birds had feathers for
>thermal regulation.

I don't have to "mind read". I just have to "read"! Here is what you
wrote:

---------------------------------------------------------
Date: Sat, 04 Apr 1998 14:09:16 -0600
To: evolution@calvin.edu
From: grmorton@waymark.net (Glenn Morton)
Subject: half-evolved feathers

[...]

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

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.
---------------------------------------------------------

If you were not claiming that "observational data" was that there
*are* "...true transitional forms...in the sense of forms containing
incipient, developing or transitional structures - such as half-
scales/half feathers...among...known fossil forms", then what were
you attacking Morris and Parker for?

>SJ>Now you are just claiming that "the scales of Longisquama" only
>>"resemble feathers." Big deal! The mere fact of resemblance means
>>nothing. Such resemblance could be just *analogy* (ie. convergence
>>due to common function), rather than *homology* (ie. inherited due
>>to common descent): ...
>>
>>The real question is whether these scales that superficially resemble
>>feathers really are on the way to becoming feathers, or whether they
>>are just are unusual scales that just look a bit like feathers.

GM>Exactly what evidence would you look for in the fossil record to
>be sure of a half-evolved feather. Anything you find can be claimed
>not to be a half evolved feather or not on the main line of descent.
>Even if we find an elongated scale on a thecodont, you could still
>claim it wasn't on the line to birds. Is there anything that would
>convince you? Can you lay out a scenario which if true, would
>convince you?

First of all, it does not "convince" even the majority of
palaeontologists!

Second, I would be convinced if, as I have posted many times before,
either of Denton's criteria were met, namely: 1. a `perfect' (or
nearly perfect) sequence of fossils documenting the transition
unambiguously; or 2. a hypothetical detailed reconstruction of the
exact sequence of transitions plus a rigorous, detailed and
plausible explanation of how and why each stage happened:

"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 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", Burnett Books: London, 1985, p55-56)

I am not prepared, like you, to believe any half-baked just-so story
based on superficial resemblances. There have been far too many
examples of that such claims backfiring in the past:

"It must be significant that nearly all the evolutionary stories I
learned as a student, from Trueman's Ostrea/Cryphea to Carruther's
Zaphrentis delanouei, have now been debunked. Similarly, my own
experience of more than twenty years' looking for evolutionary
lineages among Mesozoic Brachiopods, has proved them equally
elusive." (Ager D.V., "Proceedings of the Geological Association",
Vol. 87, No. 2, 1976, p132, in Gish D.T., "Creation Scientists
Answer Their Critics," 1993, p135)

>SJ>The fact is that being a single specimen, there is no evidence
>>that Longisquama left any descendants:

GM>See, this allows you never to have to consider ANY evidence from
>the fossil record because you can always say the above.

Not so! See above. I said "*being a single specimen*". If there
was fossil evidence of Longisquama leaving descendants, ie. more
Longisquama fossils through time, and gradual transitions becoming
more bird-like over time, then of course I would accept it.

>>>SJ>And BTW, it's a bad habit of yours to assume that you are the
>>>>only one being serious, and those who criticise your posts are just
>>>>"playing games". I assure you that in criticising the theistic
>>>>naturalistic evolution that you espouse, I am being *deadly*
>>serious!

>SJ>You just ignored this too!

GM>Yes I did ignore that. Repeating personal type charges is one of
>those things that you do that makes me not enjoy discussing things
with you.

You are truly amazing Glenn! You dish out "personal type charges"
against a person and then when that person defends himself against
those "charges", you accuse *that person* of "Repeating personal type
charges"! I am not surprised that you don't "enjoy discussing" such
"things", but if you keep making "personal type charges" about me.
then I will keep "discussing" these "things with you".

GM> So I am going to ignore it again. I have a right to
>ignore statements I find provacative and then to ignore them again
>when you insist that I respond to them. To do otherwise, reduces
>what should be an intellectual discussion into personal charges.

See above. *You* are the one who made the "personal type charge"
that I was "playing games". And then when I defended myself, you try
to "ignore" it. Then when I again brought this to your attention,
you accuse *me* of "Repeating personal type charges"! It was *your*
"personal type charge" that I was "Repeating"!

>SJ>Having said all that, I repeat that my Mediate Creationist
>>position does not deny that there may well have been "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)".

GM>I really don't believe you hold that view. If you really could
>accept transitional forms as defined above, then you would not argue
>against ALL transitional forms like you do. You hide your
>willingness to accept transitions quite well.

See below. My argument is that "true transitional forms" if they
existed, would be very rare. So my testing of evolutionist's claims
of transitonal forms is quite consistent with my position.

SJ>God may have created feathers de novo or He may have created by
>>modifying existing designs. In both cases it may have been so
>>rapid and directional that it left few traces in the fossil record
>>of the actual transition event(s).

GM>So why can't Longisquama be a transition? He lived much earlier
>than the first birds. and he had a wishbone, a bone found only in
>birds I believe.

"Longisquama" may indeed "be a transition", but between what? You
yourself are not claiming that it is an "intermediate between birds
and reptiles":

--------------------------------------------------------
Date: Mon, 13 Apr 1998 19:13:37 -0500
To: "Stephen Jones" <sejones@ibm.net>,
"evolution@calvin.edu" <evolution@calvin.edu>
From: grmorton@waymark.net (Glenn Morton)
Subject: Re: half-evolved feather pt 2

[...]

Stephen, I didn't say that Longisquama was an intermediate between
birds and reptiles. I don't know where you got this...
--------------------------------------------------------

Now you seem to be implying that "Longisquama" is "a transition"
between reptiles and "birds"? What exactly *is* your position?

Steve

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