NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/talk/origins/16636

Internet Message Format | 1993-01-24 | 8.4 KB

Path: sparky!uunet!fedfil!news
From: [e-mail] (news)
Newsgroups: talk.origins
Subject: Re: Muscle tissue from mouse to sauropod
Message-ID: <[e-mail]>
Date: 24 Jan 93 13:43:12 GMT
References: <[e-mail]^<[e-mail]>
Organization: HTE
Lines: 190

In article <[e-mail]>, [e-mail] (Alan M Feuerbacher) writes:

^>
^>We've seen one poster claim that reptile muscle is twice as good as ours,
^>and that this has been proven more dynamically than possible via microscope
^>test.  I've got three problems with this.

^>3.  It isn't even relevant.  Sauropods resembled reptiles in no way, shape,
^>or manner, and may actually have been mammals or near-mammals.  They walked
^>with their legs under them like large mammals, as opposed to reptiles other
^>than snakes, which walkin the familiar splayed manner, and their metabolism
^>was, in all likelihood, warm-blooded.

^The point was not to prove that sauropods were or were not mammals,
^but that no one knows what their physiology was.  Given that, there
^is no basis for you to assume that they were so much like Kaz that
^you can blindly apply a single scaling equation to all life forms.
^This has been experimentally proven; see below.


You've missed the entire point.  The point is, that Kazmaier is so much stronger
than any kind of animal his own weight, that in any given situation in which
he would be unable to stand due to gravity, neither would any other animal,
and certainly neither would any animal, the bulk of whose weight was devoted
not to muscle or anything useful in lifting, but to the huge digestive system
needed to handle leaves and other low-value foods.  That includes sauropod
sauropods.

The "any situation" includes the possibility of being on a planet such as
jupiter with the huge gravity thereof, as well as being scaled up to 70,000
in our (postdiluvian) perceived gravity.

The analogy with reptiles is meaningless in the case of the sauropods for
reasons mentioned, and it is also meaningless in the particular case
of the Argentinian teratorn, a 160 - 200 lb modern eagle.  As I've noted,
central asians have been attempting to breed eagles for size and strength for
all of recorded history, and they cannot get them past 25 lbs (the berkut).
Beyond that, they cannot take off or land well enough to be functional, and
this is fully documented in the book which I have mentioned (BIRD OF JOVE).





^
^The article I pointed out was from the journal _Evolution_, Vol. 45,
^No.1, February, 1991, pages 1-17, John Ruben, Department of Zoology,
^Oregon State University.
^
^Ruben stated that _Archaeopteryx'_ skeletal structure indicated that
^it supported a relatively small mass of wing muscles, compared to
^modern birds, and that because various other features indicate it
^was certainly capable of flight, something was missing.

In other words, the evidence is all there that the creature flew, but
the musculature for something its size to fly appears to have been
missing.  There is one possibility which somebody here is not even
considering, isn't there?  That is the possibility that felt gravity was
then heavily attenuated as I have mentioned, and what would be the
required musculature in our world would not be needed.



>The missing
^piece he filled in by hypothesising

This is a hypothesis based entirely on standard uniformitarian assumptions,
i.e. based on no consideration of the possibility mentioned above.

that it was "a flying ectotherm,"
^i.e., it had reptilian musculature.

Again, this doesn't help at all for the 200 lb teratorn.  You require a
general solution here;  I have provided one, Ruben has not.


He supported this by noting the
^close similarity of _Archaeopteryx'_ skeleton to certain small
^dinosaurs, which he views as most likely cold-blooded.

That's precious little to go on.


^Given this background, note what Ruben states:

^   If _Archaeopteryx_ were ectothermic, it may well have achieved
^   powered, flapping flight, as well as ground-upward, standstill
^   takeoff, with less than one-half the flight-muscle volume of
^   modern birds.

In other words, he sees the creature as having had something like
1/2 the requisite muscle mass needed for flight in our world.

^   This is related to a previously unrecognized attribute of
^   reptilian muscle physiology:  During "burst-level" activity,
^   major locomotory muscles of a number of active terrestrial
^   squamate reptiles generate at least twice the power (watts
^   kg^-1 muscle tissue) as that of birds and mammals.  Furthermore,
^   patterns of metabolic power output during intense exercise in
^   crocodiles... suggest high-power locomotory muscle tissue occurs
^   in a broad range of diapsid reptiles.

At least three problems here:

1.  It contradicts the Nielson article, and I have no apriori reason to
    prefer Ruben here.

2.  It doesn't help the Argentinian teratorn, as noted.  Some altogether
    different (and no doubt, equally fanciful) explaination will be required
    for the teratorn.

3.  There is no reason to believe that it would help the sauropod even if
    applicable, which is doubtful.  Twice the force (which you're probably
    still not even talking about) still will not help the ultrasaur, which
    would require being MORE than twice as strong as a scaled version of
    Kazmaier its own size just to stand for three seconds, much less move
    around all day long, as it actually had to.

There is the further consideration that sauropods probably never did anything
in "burst" mode.

There is the further consideration, as I've noted, that sauropods were, in
all likelihood, either mammals or something very closely related.

^   Enhanced reptilian muscle power is probably due to a variety of
^   factors, including elevated intramuscular contractile fiber
^   concentration of mitochondria-poor reptile muscle, and
^   particularly, high contractile velocity facilitated by
^   accelerated ATP turnover and high specific activities of
^   myosin-ATPase and rate-limiting ATP-forming glycolytic
^   enzymes....  Accordingly, even though lizards and mammals attain
^   similar sprint speeds..., skeletal muscle mass in reptiles is
^   less than in equivalent-size mammals (reptilian skeletal muscle
^   mass, in grams, scales according to the equation
^   0.19 [grams total body mass^1.09]; for mammals, the equation is
^   0.42 [grams total body mass^1.01].

Correct me if I'm wrong:  I should think that the Nielson article would
still hold true in terms of the max FORCE which a muscle could exert
(which is the applicable nexus in the case of sauropods), particularly
when you consider the time spans which were likely involved in any
sauropod motion.  I don't see burst activity as particularly applicable.


^   Utilization of high-power, reptile-type flight-muscle to support
^   powered flight seems consistent with _Archaeopteryx'_ relatively
^   reduced pectoral surface area....

Again, the notion of attenuated felt gravity is an equally good candidate
for an explaination and also works for the teratorn.  Reptilian flight
muscle does not work for the teratorn.


[Various] observations are
^   strongly indicative that _Archaeopteryx'_ capacity for
^   generation of flight-muscle power was at least equal to that of
^   many living birds.

The same old dilemma...  the thing flew (obvious from physiology), and yet
could not have flown given musculature and what we know about flying creatures.

There's one final little problem which I should mention which Ruben does not
even address, and which your "reptilian muscle" thesis certainly falls flat
on.

Adrien Desmond (HOT BLOODED DINOSAURS) that thorough calculations indicate
that fifty lbs or thereabouts is the absolute maximum size for any flying
creature in our world, and that beyond that, even simply holding wings in
a turn, much less flapping them, would break bones.


This corresponds quite well with what we actually observe.  The largest
flying creature which does much in the way of flapping (relatively much
for a creature the size) is the berkut, the largest specimens, such as
Atlanta, go around 24 lbs.  The largest soaring creatures which we actually
find, albatrosses, condors etc., go around 30 or 35 lbs.


All in all, this is the best attempt I have seen on t.o to refute my basic
thesis, and certainly requires an answer.  And, given time, I've no
particular problem replying to this sort of article.

I shall be out of town for the next week, so try to time any follow-ups
to arrive around 1/30.


--
Ted Holden
HTE