On Mon, 05 Jul 1999 10:27:43 +0000, mortongr@flash.net wrote:
First of all, I wish to make it clear, that I maintain that God mediately
created the first feather from a scale of a specially prepared line of
theropod dinosaurs. But that does not mean that I accept the usual run of
half-baked evolutionary `just-so stories', examples of which Susan and
Glenn present here!
SB>I was challenging the idea of "you never see a partial wing." Which you
>>seemed to be saying. In fact, you do. The flying squirrel and flying fish
>>have "partial" wings.
This is false. The flying squirrel's skin membrane between its limbs, and the
flying fish's elongated fins, are not wings, nor are they on the way to
becoming wings, in the sense of powered flight, like bats and birds. They
are the *endpoint* of an adaptation for *gliding* not flying, that was
finished tens of millions of years ago.
SB>Lungfish have "partial" limbs and so on.
Lungfish have paired *fins* that have existed unchanged for hundreds of
millions of years. They are thus not mid-way to true legs in the sense of
true powered walking. Colbert doesn't think that the lungfishes' fins were
ever on the way to becoming true legs:
"The ability of the lungfishes to breathe air is certainly suggestive of an
intermediate stage between fishes and land-living vertebrates. (In this
connection it is interesting to note that the Australian lungfish is able to
"walk" along the bottom of the rivers or pools in which it lives by using its
paired fins like legs.) Yet in spite of such specializations in the lungfishes
directed toward a method of surviving out of the water, the total evidence
points quite clearly to the fact that these vertebrates are not and never have
been on the direct line of evolution leading from fishes to the first land-
living vertebrates. Briefly the lungfishes show too many specializations,
even in the earliest known stages of their evolutionary history, for
vertebrates that might occupy an intermediate position along the line from
fishes to amphibians." (Colbert E.H., "Evolution of the Vertebrates," 1992,
pp62-63)
GM>There is a partially evolved feather on Longisquama. See my web
page > >http://www.flash.net/~mortongr/longisq.htm > >It apparently
acted as a glider wing
I am surprised that Glenn is still trotting out Longisquama's scales as an
example of "a partially evolved feather".
As I pointed out to Glenn on the Reflector previously, there is no evidence
that Longisquama's scales were anything more than long scales, and it
is hopelessly out of time sequence:
"...Longisquama is a poor-quality fossil, and the interpretation of single
elements is controversial. Longisquama lacks other characters-present in
non-avian Maniraptora-that would ally it with birds. Single features do not
overturn a hypothesis that is strongly supported by a plethora of character
evidence. Ironically, if one does use Feduccia and Martin's reasoning that
Longisquama is a close bird 'ancestor' as advocated elsewhere, 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)
Glenn's `creationist-bashing' web page article on Longisquama at:
http://www.flash.net/~grmorton/longisq.htm, still contains a number of
inaccuracies, which I had previously pointed out to him, but which he has
not yet corrected.
If Glenn disputes this, I wil post his web page article to the Reflector
and critique it again, for the benefit of new Reflectorites.
Indeed, that Glenn has to resort to such a controversial example for his
*best* evidence of a half-scale/half-feather simply confirms what he is
trying to refute, namely statements by creationists like:
"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." (Morton G.R., "Half-evolved Feathers and
Christian Accountability" 1998. http://www.flash.net/~grmorton/longisq.htm).
Steve
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"The gaps in the record are real, however. The absence of a record of
any important branching is quite phenomenal. Species are usually
static, or nearly so, for long periods, species seldom and genera never
show evolution into new species or genera but replacement of one by
another, and change is more or less abrupt..." (Wesson R.G., "Beyond
Natural Selection," [1991], MIT Press: Cambridge MA, 1994, reprint, p45)
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