> >>>>> I freely admit most of this is new to me, that when birds walk,
> >>>>> they hold their hips more or less in place while rotating
> >>>>> their knees over a large angle.
> >>>> What you mean is that the femur rotates through a small angle and the
> >>>> tibiotarsus through a large angle. And that's correct, for all birds.
> > It seems pretty clear from the linked article that this is NOT what
> > the linked article meant, and so jillery probably did not mean it
> > either. The picture accompanying the linked article labeled both the
> > hip and the knee joints, using colors to highlight them.
> I fail to see how a hip joint can move. And the knee joint moves exactly
> to the extent that the femur does.
Yeah, but jillery didn't use the word "moving" but rather "rotating"
in connection with the knee joint.
> Anyway, you misunderstand the intent
> of the diagram, which appears to be merely to locate the joints. It
> should be clear from the text that "movement around the hip joint" means
> "movement of the femur",
Yes.
> "movement around the knee joint means "movement
> of the tibiotarsus",
Not if the femur is also moving. Then the tibiotarsus has two things
contributing to its movement, the other being the rotation of the knee
joint.
Oops, you'll claim this is a pointless exception that does nothing to
advance the discussion [as below], won't you?
> and "movement around the ankle joint" means
> "movement of the tarsometatarsus".
No comment.
> "Movement of the joint" is quite
> different from "movement around the joint".
Oh, wait! suddenly YOU are talking about the pointless exception of
the knee moving because the femur is moving, and not about the
movement around the knee.
> A bird's knee moves very
> little, because the femur moves very little. A bird's ankle moves quite
> a lot, because the tibiotarsus moves quite a lot. Is that clear now?
The only unclear thing is whether you'll go childish and smart-alecky
on account of my writing, "Not if the femur is also moving...."
> > By the way, when you said "rotates" did you mean around the long
> > axis? I don't think you did, but that illustrates how the article
> > and jillery were unambiguous, while you were not.
> As is so often the case, you have difficulty interpreting simple
> statements. The usual technical term is "excursion". But yes, I meant
> around the long axis.
I'd call that twisting, not rotating. The long axis runs along the
length of the bone, the way we mathematicians use the words "long
axis".
[snip]
> > Yeah, I was really surprised to see that birds fuse THREE metatarsals;
> > I'd only heard about cannon bones of camelids and some deer (not
> > horses, where there is only one metatarsal besides the narrow splints)
> > before, and those only fuse two.
> > Spurred by this article, I did some browsing in Romer's _Vertebrate
> > Paleontology_ and saw that ornithomimids also fused three metatarsals,
> > strengthening the case for birds being (descended from) dinosaurs.
> Not really, since the fusion was entirely convergent.
Did the other maniraptorans have it?
[snip]
> >>>>> In contrast, most mammals move their hips over a much
> >>>>> larger angle than do birds, even nonflying birds.
> >>>> Nonflying birds are no different in this respect from flying birds. And
> >>>> of course mammals move their femurs over a large angle.
> >>> What about true ("earless") seals?
> >> Yeah, and what about whales? Most of them don't even have femurs, so there.
> > Have you decided to go all childish and smart-alecky when people point
> > out possible exceptions to what you write?
> No. I've decided to go all childish and smart-alecky when people raise
> pointless exceptions that contribute nothing to the discussion.
Trouble is, I still don't know whether the lack of mobility of the
hind legs of seals is mainly to be blamed on the femur or the tibia/
fibula. Similarly for bats:
> > Here's another possible REAL exception: when bats crawl along on
> > horizontal surfaces, their hind legs are so twisted, it really looks
> > like their knees bend the wrong way. [Reminds me of another recent
> > s.b.p. thread.]
[snip]
> >>>>> But theropod dinosaurs, from which birds are
> >>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
> >>>>> didn't have this limitation, but stood with their knees more-or-less
> >>>>> straight, a very unavian posture.
> >>>> Which apparently demonstrates conclusively that Archaeopteryx is not a
> >>>> bird.
> >>> I take it you are being ironic here.
> >> Good catch.
[snip]
> > You keep harping on the fact that even what looks like
> > direct ancestry from fossils could easily be falsified with more
> > complete data.
> You misunderstand. Nothing "looks like direct ancestry". There is no
> such "showing".
A complete lack of autapomorphies doesn't look like direct ancestry?
Is that because you are morally certain that autapomorphies will
eventually be discovered?
> >> It isn't lack
> >> of a complete specimen that's the problem. Now in fact Archaeopteryx has
> >> autapomorphies that argue against it being the ancestor.
> >>> Nor
> >>> is it to say that it is a candidate for the *last* common ancestor--it
> >>> clearly is not.
> >> Well, I'm glad that's settled.
> > Are you ironically implying that it still hasn't been ruled out as the
> > LCA?
> No. I'm expressing annoyance regarding your tendency to ruminate to
> yourself in public. This is ruminating to yourself because the question
> is of concern and relevance only to you.
> > Bad catch this time, I fear.
> Did you catch the ironic intent of "good catch"?
No. Are you suggesting that my observation was just too trivial to be
worth posting here? How about if this thread had been crossposted to
talk.origins, where some participants (especially creationists) might
not know you were being ironic?
> >>>>>>>> I freely admit most of this is new to me, that when birds walk,
> >>>>>>>> they hold their hips more or less in place while rotating
> >>>>>>>> their knees over a large angle.
> >>>>>>> What you mean is that the femur rotates through a small angle and the
> >>>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
> >>>> It seems pretty clear from the linked article that this is NOT what
> >>>> the linked article meant, and so jillery probably did not mean it
> >>>> either. The picture accompanying the linked article labeled both the
> >>>> hip and the knee joints, using colors to highlight them.
> >>> I fail to see how a hip joint can move. And the knee joint moves exactly
> >>> to the extent that the femur does. Anyway, you misunderstand the intent
> >>> of the diagram, which appears to be merely to locate the joints. It
> >>> should be clear from the text that "movement around the hip joint" means
> >>> "movement of the femur", "movement around the knee joint means "movement
> >>> of the tibiotarsus", and "movement around the ankle joint" means
> >>> "movement of the tarsometatarsus". "Movement of the joint" is quite
> >>> different from "movement around the joint". A bird's knee moves very
> >>> little, because the femur moves very little. A bird's ankle moves quite
> >>> a lot, because the tibiotarsus moves quite a lot. Is that clear now?
> >>>> By the way, when you said "rotates" did you mean around the long
> >>>> axis? I don't think you did, but that illustrates how the article
> >>>> and jillery were unambiguous, while you were not.
> >>> As is so often the case, you have difficulty interpreting simple
> >>> statements. The usual technical term is "excursion". But yes, I meant
> >>> around the long axis.
> >>>>>> Is the tibiotarsus homologous to our knees?
> >>>>> No. The knee is a joint, not a bone. The knee is the joint between the
> >>>>> femur and the tibia/fibula.
> >>>>>> What's the word "tarsus"
> >>>>>> doing in there?
> >>>>> And "tarsus" means "ankle". Birds have more or less the same ankle bones
> >>>>> we do, but they work differently. And they have a lot of fusion of
> >>>>> bones.
> >>>> Yeah, I was really surprised to see that birds fuse THREE metatarsals;
> >>>> I'd only heard about cannon bones of camelids and some deer (not
> >>>> horses, where there is only one metatarsal besides the narrow splints)
> >>>> before, and those only fuse two.
> >>>> Spurred by this article, I did some browsing in Romer's _Vertebrate
> >>>> Paleontology_ and saw that ornithomimids also fused three metatarsals,
> >>>> strengthening the case for birds being (descended from) dinosaurs.
> >>> Not really, since the fusion was entirely convergent.
> >>>>> Some of the bird's ankle bones are fused to the tibia; ergo,
> >>>>> "tibiotarsus". The rest of the ankle bones are fused to the metatarsals,
> >>>>> bones of the foot; ergo, "tarsometatarsus".
> >>>>>>>> In contrast, most mammals move their hips over a much
> >>>>>>>> larger angle than do birds, even nonflying birds.
> >>>>>>> Nonflying birds are no different in this respect from flying birds. And
> >>>>>>> of course mammals move their femurs over a large angle.
> >>>>>> What about true ("earless") seals?
> >>>>> Yeah, and what about whales? Most of them don't even have femurs, so there.
> >>>> Have you decided to go all childish and smart-alecky when people point
> >>>> out possible exceptions to what you write?
> >>> No. I've decided to go all childish and smart-alecky when people raise
> >>> pointless exceptions that contribute nothing to the discussion.
> >>>> Here's another possible REAL exception: when bats crawl along on
> >>>> horizontal surfaces, their hind legs are so twisted, it really looks
> >>>> like their knees bend the wrong way. [Reminds me of another recent
> >>>> s.b.p. thread.]
> >>>>>>>> Apparently even
> >>>>>>>> penguins stand in a kind of squat, with their thighs close to the
> >>>>>>>> abdomen and their knees bent.
> >>>>>>>> According to Quick and Ruben, this adaptation is necessary in order to
> >>>>>>>> support the posterior air sac during inspiration, that auxiliary
> >>>>>>>> structures like gastralia and uncinate processes don't prevent its
> >>>>>>>> paradoxical collapse. But theropod dinosaurs, from which birds are
> >>>>>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
> >>>>>>>> didn't have this limitation, but stood with their knees more-or-less
> >>>>>>>> straight, a very unavian posture.
> >>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is not a
> >>>>>>> bird.
> >>>>>> I take it you are being ironic here.
> >>>>> Good catch.
> >>>>>> Archaeopteryx has never been
> >>>>>> ruled out as a common ancestor of all extant birds, has it?
> >>>>> Do you really want to start that argument again? Trying to assign
> >>>>> ancestry to taxa is a useless exercise.
> >>>> False dichotomy. There's a huge gray area between "prove" and "rule
> >>>> out".
> >>> Agreed. But there's a similar problem with certainty. Still, the cases
> >>> are not symmetrical: we can place a low probability on ancestry, but we
> >>> can almost never place a high probability. However, I don't see the
> >>> point of failing to rule out ancestry, since we learn nothing.
> >>>>>> That's not to say that it will ever be shown to *be* a common ancestor
> >>>>>> (at least not to the satisfaction of cladists, to whom lack of access
> >>>>>> to a complete specimen is enough to rule out such a "showing").
> >>>>> I have no idea where you could ever have got that notion.
> >>>> From you. You keep harping on the fact that even what looks like
> >>>> direct ancestry from fossils could easily be falsified with more
> >>>> complete data.
> >>> You misunderstand. Nothing "looks like direct ancestry". There is no
> >>> such "showing".
> >>>>> It isn't lack
> >>>>> of a complete specimen that's the problem. Now in fact Archaeopteryx has
> >>>>> autapomorphies that argue against it being the ancestor.
> >>>> Ah, but are those autapomorphies significant enough to argue against
> >>>> some other species of Archaeopteryx than the ones discovered so far
> >>>> being direct ancestors?
> >>> Since any taxon "Archaeopteryx" would be arbitrarily delimited from
> >>> other birds, it's a meaningless question.
> >>>> I realize I am treading on controversial ground here: once upon a
> >>>> time, the Berlin specimen of Archaeopteryx was given a whole new
> >>>> genus, Archaeornis. The splitters lost out on that one, big-time:
> >>>> they are even considered to be the same species these days.
> >>> Actually, there's some question on that. But your apprehension is
> >>> meaningless.
> >>>>>> Nor
> >>>>>> is it to say that it is a candidate for the *last* common ancestor--it
> >>>>>> clearly is not.
> >>>>> Well, I'm glad that's settled.
> >>>> Are you ironically implying that it still hasn't been ruled out as the
> >>>> LCA?
> >>> No. I'm expressing annoyance regarding your tendency to ruminate to
> >>> yourself in public. This is ruminating to yourself because the question
> >>> is of concern and relevance only to you.
> >>>> Bad catch this time, I fear.
> >>> Did you catch the ironic intent of "good catch"?
> >> I think I'll walk away in bemusement.
> >I apologize to any other irony-impaired readers for their difficulty in
> >interpreting my remarks. But I refuse to employ emoticons. :)
> You're right, Pnyikos doesn't deserve an apology over this.
Jillery doesn't think I deserve an apology over being repeatedly
slandered by certain buddies of hers/his, so why does [s]he even
bother writing "over this" and writing "an apology" instead of "any
apologies"?
>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>> they hold their hips more or less in place while rotating
>>>>>>> their knees over a large angle.
>>>>>> What you mean is that the femur rotates through a small angle and the
>>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
>>> It seems pretty clear from the linked article that this is NOT what
>>> the linked article meant, and so jillery probably did not mean it
>>> either. The picture accompanying the linked article labeled both the
>>> hip and the knee joints, using colors to highlight them.
>> I fail to see how a hip joint can move. And the knee joint moves exactly
>> to the extent that the femur does.
> Yeah, but jillery didn't use the word "moving" but rather "rotating"
> in connection with the knee joint.
Why should it matter what words jillery used? What should matter is what happens. What article meant, and what jillery presumably meant based on the article, was what I said.
>> Anyway, you misunderstand the intent
>> of the diagram, which appears to be merely to locate the joints. It
>> should be clear from the text that "movement around the hip joint" means
>> "movement of the femur",
> Yes.
>> "movement around the knee joint means "movement
>> of the tibiotarsus",
> Not if the femur is also moving. Then the tibiotarsus has two things
> contributing to its movement, the other being the rotation of the knee
> joint.
> Oops, you'll claim this is a pointless exception that does nothing to
> advance the discussion [as below], won't you?
Depends. What exactly do you mean by "rotation of the knee joint"? If you mean "movement of the distal end of the femur", then that's the only thing contributing to movement of the knee joint. We have to separate movement of the knee joint from movement around the knee joint, which are two entirely separate things. Movement *of* the knee joint (i.e. movement of the femur) contributes only a small amount to movement of the leg. Movement *around* the knee joint contributes a much greater amount. Don't confuse the two.
>> and "movement around the ankle joint" means
>> "movement of the tarsometatarsus".
> No comment.
>> "Movement of the joint" is quite
>> different from "movement around the joint".
> Oh, wait! suddenly YOU are talking about the pointless exception of
> the knee moving because the femur is moving, and not about the
> movement around the knee.
No, I'm talking about the difference between the two.
>> A bird's knee moves very
>> little, because the femur moves very little. A bird's ankle moves quite
>> a lot, because the tibiotarsus moves quite a lot. Is that clear now?
> The only unclear thing is whether you'll go childish and smart-alecky
> on account of my writing, "Not if the femur is also moving...."
Is explaining why you're wrong to conflate the two "childish and smart-alecky"?
>>> By the way, when you said "rotates" did you mean around the long
>>> axis? I don't think you did, but that illustrates how the article
>>> and jillery were unambiguous, while you were not.
>> As is so often the case, you have difficulty interpreting simple
>> statements. The usual technical term is "excursion". But yes, I meant
>> around the long axis.
> I'd call that twisting, not rotating. The long axis runs along the
> length of the bone, the way we mathematicians use the words "long
> axis".
Oops, sorry. I didn't mean that. This time I misunderstood you. I meant movement *of* the long axis in approximately a parasagittal plane. You know, what we normally think of as a walking motion.
>>> Yeah, I was really surprised to see that birds fuse THREE metatarsals;
>>> I'd only heard about cannon bones of camelids and some deer (not
>>> horses, where there is only one metatarsal besides the narrow splints)
>>> before, and those only fuse two.
>>> Spurred by this article, I did some browsing in Romer's _Vertebrate
>>> Paleontology_ and saw that ornithomimids also fused three metatarsals,
>>> strengthening the case for birds being (descended from) dinosaurs.
>> Not really, since the fusion was entirely convergent.
> Did the other maniraptorans have it?
Most did not. Think of Tyrannosaurus, for example. Archaeopteryx also, as far as I recall, has no metatarsal fusion. It's a later development in birds.
>>>>>>> In contrast, most mammals move their hips over a much
>>>>>>> larger angle than do birds, even nonflying birds.
>>>>>> Nonflying birds are no different in this respect from flying birds. And
>>>>>> of course mammals move their femurs over a large angle.
>>>>> What about true ("earless") seals?
>>>> Yeah, and what about whales? Most of them don't even have femurs, so there.
>>> Have you decided to go all childish and smart-alecky when people point
>>> out possible exceptions to what you write?
>> No. I've decided to go all childish and smart-alecky when people raise
>> pointless exceptions that contribute nothing to the discussion.
> Trouble is, I still don't know whether the lack of mobility of the
> hind legs of seals is mainly to be blamed on the femur or the tibia/
> fibula. Similarly for bats:
>>> Here's another possible REAL exception: when bats crawl along on
>>> horizontal surfaces, their hind legs are so twisted, it really looks
>>> like their knees bend the wrong way. [Reminds me of another recent
>>> s.b.p. thread.]
> [snip]
>>>>>>> But theropod dinosaurs, from which birds are
>>>>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
>>>>>>> didn't have this limitation, but stood with their knees more-or-less
>>>>>>> straight, a very unavian posture.
>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is not a
>>>>>> bird.
>>>>> I take it you are being ironic here.
>>>> Good catch.
> [snip]
>>> You keep harping on the fact that even what looks like
>>> direct ancestry from fossils could easily be falsified with more
>>> complete data.
>> You misunderstand. Nothing "looks like direct ancestry". There is no
>> such "showing".
> A complete lack of autapomorphies doesn't look like direct ancestry?
> Is that because you are morally certain that autapomorphies will
> eventually be discovered?
No. But there is no reason to suppose that a lack of skeletal apomorphies shows a lack of divergence in other characters, even if only genetic ones. A lack of apomorphies merely fails to argue against ancestry, just as a photo of a lightless room fails to argue about the presence of an elephant. Does a lightless room look like an elephant?
>>>> It isn't lack
>>>> of a complete specimen that's the problem. Now in fact Archaeopteryx has
>>>> autapomorphies that argue against it being the ancestor.
> [snip]
>>>>> Nor
>>>>> is it to say that it is a candidate for the *last* common ancestor--it
>>>>> clearly is not.
>>>> Well, I'm glad that's settled.
>>> Are you ironically implying that it still hasn't been ruled out as the
>>> LCA?
>> No. I'm expressing annoyance regarding your tendency to ruminate to
>> yourself in public. This is ruminating to yourself because the question
>> is of concern and relevance only to you.
>>> Bad catch this time, I fear.
>> Did you catch the ironic intent of "good catch"?
> No. Are you suggesting that my observation was just too trivial to be
> worth posting here?
Yes. Good catch.
> How about if this thread had been crossposted to
> talk.origins, where some participants (especially creationists) might
> not know you were being ironic?
Revisiting a Science Daily article jillery posted about to
sci.bio.paleontology, I am struck by some strange language in it,
which might lead an unsophisticated reader to think that John Ruben
and Devon Quick, on the faculty of Oregon State University, had
serious doubts about common descent of tetrapods, let alone all
animals, let alone all life:
"We aren't suggesting that dinosaurs
and birds may not have had a common
ancestor somewhere in the distant past,"
Quick said. "That's quite possible and
is routinely found in evolution."
http://www.sciencedaily.com/releases/2009/06/090609092055.htm
But as several people, especially John Harshman, know, Ruben only
denies that birds are descended from dinosaurs. As an old-fashioned
systematist would say, he believes they are descended from thecodonts,
and Quick probably believes this too. Now that this old-fashioned
language has been "discredited," awkward language such as the above
can be found all over the place.
Most of the article is about respiration in birds, and has Ruben and
Quick on a soapbox about their pet theory.
Back in sci.bio.paleontology, the discussion centered on certain
features of avian leg movement that enable deeper breathing by them.
On Oct 11, 11:20 am, John Harshman <jharsh...@pacbell.net> wrote:
> On 10/10/12 9:30 PM, pnyikos wrote:
> > On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
> >> On 10/5/12 10:38 AM, pnyikos wrote:
> >>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
> >>>> On 9/28/12 8:01 PM, pnyikos wrote:
> >>>>> On Sep 21, 11:36 am, John Harshman<jharsh...@pacbell.net> wrote:
> >>>>>> jillery wrote:
> >>>>>>> I freely admit most of this is new to me, that when birds walk,
> >>>>>>> they hold their hips more or less in place while rotating
> >>>>>>> their knees over a large angle.
> >>>>>> What you mean is that the femur rotates through a small angle and the
> >>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
> >>> It seems pretty clear from the linked article that this is NOT what
> >>> the linked article meant, and so jillery probably did not mean it
> >>> either. The picture accompanying the linked article labeled both the
> >>> hip and the knee joints, using colors to highlight them.
> >> I fail to see how a hip joint can move. And the knee joint moves exactly
> >> to the extent that the femur does.
> > Yeah, but jillery didn't use the word "moving" but rather "rotating"
> > in connection with the knee joint.
> Why should it matter what words jillery used? What should matter is what
> happens. What article meant, and what jillery presumably meant based on
> the article, was what I said.
Perhaps what you write is synonymous with what the article said, but
its actual words the article uses start out closer to those of jillery
than to yours:
During walking and running in birds,
hindlimb movement is generated primarily
at the knee and ankle joints; in humans,
movement occurs at the knee, ankle and hip joints.
Only the last part of the caption says what you do, and only half of
it, and it seems clear that this all is due to the lack of mobility in
the hip joint:
The bird's thigh does not move substantially
from its nearly horizontal position where it
provides rigid lateral support to the thin walled
air-sacs of the respiratory system.
[snip of mostly s.b.p. shop talk, some of which will be replied to
there in a few minutes]
> >>>>>>> But theropod dinosaurs, from which birds are
> >>>>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
> >>>>>>> didn't have this limitation, but stood with their knees more-or-less
> >>>>>>> straight, a very unavian posture.
> >>>>>> Which apparently demonstrates conclusively that Archaeopteryx is not a
> >>>>>> bird.
> >>>>> I take it you are being ironic here.
> >>>> Good catch.
> > [snip]
[snip of mostly s.b.p. shop talk]
> >> Did you catch the ironic intent of "good catch"?
> > No. Are you suggesting that my observation was just too trivial to be
> > worth posting here?
> Yes. Good catch.
I suspect that you mean it this time.
> > How about if this thread had been crossposted to
> > talk.origins, where some participants (especially creationists) might
> > not know you were being ironic?
> Still yes.
Well, I've crossposted this to talk.origins. Let's see whether the
folks over there agree.
> >>>>>>> I freely admit most of this is new to me, that when birds walk,
> >>>>>>> they hold their hips more or less in place while rotating
> >>>>>>> their knees over a large angle.
> >>>>>> What you mean is that the femur rotates through a small angle and the
> >>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
> >>> It seems pretty clear from the linked article that this is NOT what
> >>> the linked article meant, and so jillery probably did not mean it
> >>> either. The picture accompanying the linked article labeled both the
> >>> hip and the knee joints, using colors to highlight them.
[snip things addressed in my first reply]
> >> Anyway, you misunderstand the intent
> >> of the diagram, which appears to be merely to locate the joints. It
> >> should be clear from the text that "movement around the hip joint" means
> >> "movement of the femur",
> > Yes.
However, a better way of saying it is that range of movement of the
femur is *dependent* on mobility of the hip joint.
> >> "movement around the knee joint means "movement
> >> of the tibiotarsus",
> > Not if the femur is also moving. Then the tibiotarsus has two things
> > contributing to its movement, the other being the rotation of the knee
> > joint.
> > Oops, you'll claim this is a pointless exception that does nothing to
> > advance the discussion [as below], won't you?
> Depends. What exactly do you mean by "rotation of the knee joint"? If
> you mean "movement of the distal end of the femur", then that's the only
> thing contributing to movement of the knee joint.
That is not what I mean. As I sit here in my chair, my thigh is
immobile, and yet I can kick with my feet because my knee joints are
free to rotate. This rotation is effected by muscles that contract,
moving my tibia (and maybe fibula) through a wide arc.
That's the way I use "rotate". From what you say below, I might have
conveyed my thoughts better to you if I had said "rotation around the
knee joint" rather than just "rotation of the knee joint."
> We have to separate
> movement of the knee joint from movement around the knee joint, which
> are two entirely separate things. Movement *of* the knee joint (i.e.
> movement of the femur) contributes only a small amount to movement of
> the leg. Movement *around* the knee joint contributes a much greater
> amount. Don't confuse the two.
I never did. And I hope my (and maybe jillery's) use of "rotating"
won't cause you any more problems.
> >> and "movement around the ankle joint" means
> >> "movement of the tarsometatarsus".
> > No comment.
> >> "Movement of the joint" is quite
> >> different from "movement around the joint".
> > Oh, wait! suddenly YOU are talking about the pointless exception of
> > the knee moving because the femur is moving, and not about the
> > movement around the knee.
> No, I'm talking about the difference between the two.
Why even bring the "movement of the joint" into the picture? That
talks about change of location, not anything to do with what either
the article, or jillery, or I talked about.
[snip]
> >>> By the way, when you said "rotates" did you mean around the long
> >>> axis? I don't think you did, but that illustrates how the article
> >>> and jillery were unambiguous, while you were not.
> >> As is so often the case, you have difficulty interpreting simple
> >> statements. The usual technical term is "excursion". But yes, I meant
> >> around the long axis.
> > I'd call that twisting, not rotating. The long axis runs along the
> > length of the bone, the way we mathematicians use the words "long
> > axis".
> Oops, sorry. I didn't mean that. This time I misunderstood you. I meant
> movement *of* the long axis in approximately a parasagittal plane. You
> know, what we normally think of as a walking motion.
Well, I'm glad we cleared that up. Hope we cleared the part about
"rotation" up this time.
> Revisiting a Science Daily article jillery posted about to
> sci.bio.paleontology, I am struck by some strange language in it,
> which might lead an unsophisticated reader to think that John Ruben
> and Devon Quick, on the faculty of Oregon State University, had
> serious doubts about common descent of tetrapods, let alone all
> animals, let alone all life:
> "We aren't suggesting that dinosaurs
> and birds may not have had a common
> ancestor somewhere in the distant past,"
> Quick said. "That's quite possible and
> is routinely found in evolution."
> http://www.sciencedaily.com/releases/2009/06/090609092055.htm
> But as several people, especially John Harshman, know, Ruben only
> denies that birds are descended from dinosaurs.
Why "especially"?
> As an old-fashioned
> systematist would say, he believes they are descended from thecodonts,
> and Quick probably believes this too.
Actually, Ruben never really says what he thinks. Dunno about Quick.
> Now that this old-fashioned
> language has been "discredited," awkward language such as the above
> can be found all over the place.
> Most of the article is about respiration in birds, and has Ruben and
> Quick on a soapbox about their pet theory.
> Back in sci.bio.paleontology, the discussion centered on certain
> features of avian leg movement that enable deeper breathing by them.
> On Oct 11, 11:20 am, John Harshman<jharsh...@pacbell.net> wrote:
>> On 10/10/12 9:30 PM, pnyikos wrote:
>>> On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>>> On 10/5/12 10:38 AM, pnyikos wrote:
>>>>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>> On 9/28/12 8:01 PM, pnyikos wrote:
>>>>>>> On Sep 21, 11:36 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>>> jillery wrote:
>>>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>>>> they hold their hips more or less in place while rotating
>>>>>>>>> their knees over a large angle.
>>>>>>>> What you mean is that the femur rotates through a small angle and the
>>>>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
>>>>> It seems pretty clear from the linked article that this is NOT what
>>>>> the linked article meant, and so jillery probably did not mean it
>>>>> either. The picture accompanying the linked article labeled both the
>>>>> hip and the knee joints, using colors to highlight them.
>>>> I fail to see how a hip joint can move. And the knee joint moves exactly
>>>> to the extent that the femur does.
>>> Yeah, but jillery didn't use the word "moving" but rather "rotating"
>>> in connection with the knee joint.
>> Why should it matter what words jillery used? What should matter is what
>> happens. What article meant, and what jillery presumably meant based on
>> the article, was what I said.
> Perhaps what you write is synonymous with what the article said, but
> its actual words the article uses start out closer to those of jillery
> than to yours:
> During walking and running in birds,
> hindlimb movement is generated primarily
> at the knee and ankle joints; in humans,
> movement occurs at the knee, ankle and hip joints.
Only if you misunderstand what that sentence says, perhaps by interpreting "at" to mean "by". To be excruciatingly clear: movement is generated at a joint (at least the joints we're talking about) by rotation in a parasagittal plane of the distal element. Movement at the hip is movement of the femur; movement at the knee is movement of the tibiotarsus; movement at the ankle is movement of the tarsometatarsus. Ruben and Quick say exactly this, if you have the sense to read what they say.
> Only the last part of the caption says what you do, and only half of
> it, and it seems clear that this all is due to the lack of mobility in
> the hip joint:
> The bird's thigh does not move substantially
> from its nearly horizontal position where it
> provides rigid lateral support to the thin walled
> air-sacs of the respiratory system.
I have no idea what you intend "lack of mobility in the hip joint" to mean. I'm not sure you know what you mean, or what your point is.
> [snip of mostly s.b.p. shop talk, some of which will be replied to
> there in a few minutes]
>>>>>>>>> But theropod dinosaurs, from which birds are
>>>>>>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
>>>>>>>>> didn't have this limitation, but stood with their knees more-or-less
>>>>>>>>> straight, a very unavian posture.
>>>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is not a
>>>>>>>> bird.
>>>>>>> I take it you are being ironic here.
>>>>>> Good catch.
>>> [snip]
> [snip of mostly s.b.p. shop talk]
>>>> Did you catch the ironic intent of "good catch"?
>>> No. Are you suggesting that my observation was just too trivial to be
>>> worth posting here?
>> Yes. Good catch.
> I suspect that you mean it this time.
Your suspicions, as so often, are not warranted.
>>> How about if this thread had been crossposted to
>>> talk.origins, where some participants (especially creationists) might
>>> not know you were being ironic?
>> Still yes.
> Well, I've crossposted this to talk.origins. Let's see whether the
> folks over there agree.
Agree with what? I don't really understand why you're posting this.
> On Oct 11, 11:20 am, John Harshman<jharsh...@pacbell.net> wrote:
>> On 10/10/12 9:30 PM, pnyikos wrote:
>>> On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>>> On 10/5/12 10:38 AM, pnyikos wrote:
>>>>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>> On 9/28/12 8:01 PM, pnyikos wrote:
>>>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>>>> they hold their hips more or less in place while rotating
>>>>>>>>> their knees over a large angle.
>>>>>>>> What you mean is that the femur rotates through a small angle and the
>>>>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
>>>>> It seems pretty clear from the linked article that this is NOT what
>>>>> the linked article meant, and so jillery probably did not mean it
>>>>> either. The picture accompanying the linked article labeled both the
>>>>> hip and the knee joints, using colors to highlight them.
> [snip things addressed in my first reply]
>>>> Anyway, you misunderstand the intent
>>>> of the diagram, which appears to be merely to locate the joints. It
>>>> should be clear from the text that "movement around the hip joint" means
>>>> "movement of the femur",
>>> Yes.
> However, a better way of saying it is that range of movement of the
> femur is *dependent* on mobility of the hip joint.
That would depend on what "mobility of the hip joint" means. But I don't consider that a better way at all.
>>>> "movement around the knee joint means "movement
>>>> of the tibiotarsus",
>>> Not if the femur is also moving. Then the tibiotarsus has two things
>>> contributing to its movement, the other being the rotation of the knee
>>> joint.
>>> Oops, you'll claim this is a pointless exception that does nothing to
>>> advance the discussion [as below], won't you?
>> Depends. What exactly do you mean by "rotation of the knee joint"? If
>> you mean "movement of the distal end of the femur", then that's the only
>> thing contributing to movement of the knee joint.
> That is not what I mean. As I sit here in my chair, my thigh is
> immobile, and yet I can kick with my feet because my knee joints are
> free to rotate. This rotation is effected by muscles that contract,
> moving my tibia (and maybe fibula) through a wide arc.
No, the joint isn't rotating. Your tibia and fibula are rotating. The joint is in fact stationary. If you can move your tibia in a wide arc without moving your fibula in a very similar arc, you have a very unusual anatomy.
> That's the way I use "rotate". From what you say below, I might have
> conveyed my thoughts better to you if I had said "rotation around the
> knee joint" rather than just "rotation of the knee joint."
Exactly. The two mean quite different things.
>> We have to separate
>> movement of the knee joint from movement around the knee joint, which
>> are two entirely separate things. Movement *of* the knee joint (i.e.
>> movement of the femur) contributes only a small amount to movement of
>> the leg. Movement *around* the knee joint contributes a much greater
>> amount. Don't confuse the two.
> I never did. And I hope my (and maybe jillery's) use of "rotating"
> won't cause you any more problems.
If you didn't confuse the two, what are we arguing about? What in fact do you think the linked article meant?
>>>> and "movement around the ankle joint" means
>>>> "movement of the tarsometatarsus".
>>> No comment.
>>>> "Movement of the joint" is quite
>>>> different from "movement around the joint".
>>> Oh, wait! suddenly YOU are talking about the pointless exception of
>>> the knee moving because the femur is moving, and not about the
>>> movement around the knee.
>> No, I'm talking about the difference between the two.
> Why even bring the "movement of the joint" into the picture? That
> talks about change of location, not anything to do with what either
> the article, or jillery, or I talked about.
"Movement of the joint" is what you said. If that isn't what you meant, what is our disagreement?
>>>>> By the way, when you said "rotates" did you mean around the long
>>>>> axis? I don't think you did, but that illustrates how the article
>>>>> and jillery were unambiguous, while you were not.
>>>> As is so often the case, you have difficulty interpreting simple
>>>> statements. The usual technical term is "excursion". But yes, I meant
>>>> around the long axis.
>>> I'd call that twisting, not rotating. The long axis runs along the
>>> length of the bone, the way we mathematicians use the words "long
>>> axis".
>> Oops, sorry. I didn't mean that. This time I misunderstood you. I meant
>> movement *of* the long axis in approximately a parasagittal plane. You
>> know, what we normally think of as a walking motion.
> Well, I'm glad we cleared that up. Hope we cleared the part about
> "rotation" up this time.
What was the point of your initial post? Did you have one?
> On 10/11/12 7:49 PM, pnyikos wrote:
>> Revisiting a Science Daily article jillery posted about to
>> sci.bio.paleontology, I am struck by some strange language in it,
>> which might lead an unsophisticated reader to think that John Ruben
>> and Devon Quick, on the faculty of Oregon State University, had
>> serious doubts about common descent of tetrapods, let alone all
>> animals, let alone all life:
>> "We aren't suggesting that dinosaurs
>> and birds may not have had a common
>> ancestor somewhere in the distant past,"
>> Quick said. "That's quite possible and
>> is routinely found in evolution."
>> http://www.sciencedaily.com/releases/2009/06/090609092055.htm
>> But as several people, especially John Harshman, know, Ruben only
>> denies that birds are descended from dinosaurs.
> Why "especially"?
>> As an old-fashioned
>> systematist would say, he believes they are descended from thecodonts,
>> and Quick probably believes this too.
> Actually, Ruben never really says what he thinks. Dunno about Quick.
>> Now that this old-fashioned
>> language has been "discredited," awkward language such as the above
>> can be found all over the place.
> Please. Don't blame poor writing on cladistics.
>> Most of the article is about respiration in birds, and has Ruben and
>> Quick on a soapbox about their pet theory.
>> Back in sci.bio.paleontology, the discussion centered on certain
>> features of avian leg movement that enable deeper breathing by them.
>> On Oct 11, 11:20 am, John Harshman<jharsh...@pacbell.net> wrote:
>>> On 10/10/12 9:30 PM, pnyikos wrote:
>>>> On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>>>> On 10/5/12 10:38 AM, pnyikos wrote:
>>>>>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>> On 9/28/12 8:01 PM, pnyikos wrote:
>>>>>>>> On Sep 21, 11:36 am, John Harshman<jharsh...@pacbell.net>
>>>>>>>> wrote:
>>>>>>>>> jillery wrote:
>>>>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>>>>> they hold their hips more or less in place while rotating
>>>>>>>>>> their knees over a large angle.
>>>>>>>>> What you mean is that the femur rotates through a small angle and the
>>>>>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
>>>>>> It seems pretty clear from the linked article that this is NOT what
>>>>>> the linked article meant, and so jillery probably did not mean it
>>>>>> either. The picture accompanying the linked article labeled both the
>>>>>> hip and the knee joints, using colors to highlight them.
>>>>> I fail to see how a hip joint can move. And the knee joint moves exactly
>>>>> to the extent that the femur does.
>>>> Yeah, but jillery didn't use the word "moving" but rather "rotating"
>>>> in connection with the knee joint.
>>> Why should it matter what words jillery used? What should matter is what
>>> happens. What article meant, and what jillery presumably meant based on
>>> the article, was what I said.
>> Perhaps what you write is synonymous with what the article said, but
>> its actual words the article uses start out closer to those of jillery
>> than to yours:
>> During walking and running in birds,
>> hindlimb movement is generated primarily
>> at the knee and ankle joints; in humans,
>> movement occurs at the knee, ankle and hip joints.
> Only if you misunderstand what that sentence says, perhaps by > interpreting "at" to mean "by". To be excruciatingly clear: movement is > generated at a joint (at least the joints we're talking about) by > rotation in a parasagittal plane of the distal element. Movement at the > hip is movement of the femur; movement at the knee is movement of the > tibiotarsus; movement at the ankle is movement of the tarsometatarsus. > Ruben and Quick say exactly this, if you have the sense to read what > they say.
Well, Peter N _is_ the leading expert at arguing from false premises.
>> Only the last part of the caption says what you do, and only half of
>> it, and it seems clear that this all is due to the lack of mobility in
>> the hip joint:
>> The bird's thigh does not move substantially
>> from its nearly horizontal position where it
>> provides rigid lateral support to the thin walled
>> air-sacs of the respiratory system.
> I have no idea what you intend "lack of mobility in the hip joint" to > mean. I'm not sure you know what you mean, or what your point is.
His only point is to mount an unwarranted attack on someone much more honest than he is.
>> [snip of mostly s.b.p. shop talk, some of which will be replied to
>> there in a few minutes]
>>>>>>>>>> But theropod dinosaurs, from which birds are
>>>>>>>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
>>>>>>>>>> didn't have this limitation, but stood with their knees more-or-less
>>>>>>>>>> straight, a very unavian posture.
>>>>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is not >>>>>>>>> a
>>>>>>>>> bird.
>>>>>>>> I take it you are being ironic here.
>>>>>>> Good catch.
>>>> [snip]
>> [snip of mostly s.b.p. shop talk]
>>>>> Did you catch the ironic intent of "good catch"?
>>>> No. Are you suggesting that my observation was just too trivial to be
>>>> worth posting here?
>>> Yes. Good catch.
>> I suspect that you mean it this time.
> Your suspicions, as so often, are not warranted.
Of course not.
>>>> How about if this thread had been crossposted to
>>>> talk.origins, where some participants (especially creationists) might
>>>> not know you were being ironic?
>>> Still yes.
>> Well, I've crossposted this to talk.origins. Let's see whether the
>> folks over there agree.
> Agree with what? I don't really understand why you're posting this.
Oh, that's clear enough. The Lord of Liars is attempting to open a second front on his assault on jillery, and is doing as well as could be expected, given his limitations.
<try.not...@but.see.sig> wrote:
>On Thu, 11 Oct 2012 23:25:51 -0400, John Harshman wrote
>(in article <OZKdnWTMUfZdEOrNRVn_...@giganews.com>):
>> On 10/11/12 7:49 PM, pnyikos wrote:
>>> Revisiting a Science Daily article jillery posted about to
>>> sci.bio.paleontology, I am struck by some strange language in it,
>>> which might lead an unsophisticated reader to think that John Ruben
>>> and Devon Quick, on the faculty of Oregon State University, had
>>> serious doubts about common descent of tetrapods, let alone all
>>> animals, let alone all life:
>>> "We aren't suggesting that dinosaurs
>>> and birds may not have had a common
>>> ancestor somewhere in the distant past,"
>>> Quick said. "That's quite possible and
>>> is routinely found in evolution."
>>> http://www.sciencedaily.com/releases/2009/06/090609092055.htm
>>> But as several people, especially John Harshman, know, Ruben only
>>> denies that birds are descended from dinosaurs.
>> Why "especially"?
>>> As an old-fashioned
>>> systematist would say, he believes they are descended from thecodonts,
>>> and Quick probably believes this too.
>> Actually, Ruben never really says what he thinks. Dunno about Quick.
>>> Now that this old-fashioned
>>> language has been "discredited," awkward language such as the above
>>> can be found all over the place.
>> Please. Don't blame poor writing on cladistics.
>>> Most of the article is about respiration in birds, and has Ruben and
>>> Quick on a soapbox about their pet theory.
>>> Back in sci.bio.paleontology, the discussion centered on certain
>>> features of avian leg movement that enable deeper breathing by them.
>>> On Oct 11, 11:20 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>> On 10/10/12 9:30 PM, pnyikos wrote:
>>>>> On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>> On 10/5/12 10:38 AM, pnyikos wrote:
>>>>>>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>>> On 9/28/12 8:01 PM, pnyikos wrote:
>>>>>>>>> On Sep 21, 11:36 am, John Harshman<jharsh...@pacbell.net>
>>>>>>>>> wrote:
>>>>>>>>>> jillery wrote:
>>>>>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>>>>>> they hold their hips more or less in place while rotating
>>>>>>>>>>> their knees over a large angle.
>>>>>>>>>> What you mean is that the femur rotates through a small angle and the
>>>>>>>>>> tibiotarsus through a large angle. And that's correct, for all birds.
>>>>>>> It seems pretty clear from the linked article that this is NOT what
>>>>>>> the linked article meant, and so jillery probably did not mean it
>>>>>>> either. The picture accompanying the linked article labeled both the
>>>>>>> hip and the knee joints, using colors to highlight them.
>>>>>> I fail to see how a hip joint can move. And the knee joint moves exactly
>>>>>> to the extent that the femur does.
>>>>> Yeah, but jillery didn't use the word "moving" but rather "rotating"
>>>>> in connection with the knee joint.
>>>> Why should it matter what words jillery used? What should matter is what
>>>> happens. What article meant, and what jillery presumably meant based on
>>>> the article, was what I said.
>>> Perhaps what you write is synonymous with what the article said, but
>>> its actual words the article uses start out closer to those of jillery
>>> than to yours:
>>> During walking and running in birds,
>>> hindlimb movement is generated primarily
>>> at the knee and ankle joints; in humans,
>>> movement occurs at the knee, ankle and hip joints.
>> Only if you misunderstand what that sentence says, perhaps by >> interpreting "at" to mean "by". To be excruciatingly clear: movement is >> generated at a joint (at least the joints we're talking about) by >> rotation in a parasagittal plane of the distal element. Movement at the >> hip is movement of the femur; movement at the knee is movement of the >> tibiotarsus; movement at the ankle is movement of the tarsometatarsus. >> Ruben and Quick say exactly this, if you have the sense to read what >> they say.
>Well, Peter N _is_ the leading expert at arguing from false premises.
>>> Only the last part of the caption says what you do, and only half of
>>> it, and it seems clear that this all is due to the lack of mobility in
>>> the hip joint:
>>> The bird's thigh does not move substantially
>>> from its nearly horizontal position where it
>>> provides rigid lateral support to the thin walled
>>> air-sacs of the respiratory system.
>> I have no idea what you intend "lack of mobility in the hip joint" to >> mean. I'm not sure you know what you mean, or what your point is.
>His only point is to mount an unwarranted attack on someone much more honest >than he is.
>>> [snip of mostly s.b.p. shop talk, some of which will be replied to
>>> there in a few minutes]
>>>>>>>>>>> But theropod dinosaurs, from which birds are
>>>>>>>>>>> supposed to have evolved, including velociraptors and Archaeopteryx,
>>>>>>>>>>> didn't have this limitation, but stood with their knees more-or-less
>>>>>>>>>>> straight, a very unavian posture.
>>>>>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is not >>>>>>>>>> a
>>>>>>>>>> bird.
>>>>>>>>> I take it you are being ironic here.
>>>>>>>> Good catch.
>>>>> [snip]
>>> [snip of mostly s.b.p. shop talk]
>>>>>> Did you catch the ironic intent of "good catch"?
>>>>> No. Are you suggesting that my observation was just too trivial to be
>>>>> worth posting here?
>>>> Yes. Good catch.
>>> I suspect that you mean it this time.
>> Your suspicions, as so often, are not warranted.
>Of course not.
>>>>> How about if this thread had been crossposted to
>>>>> talk.origins, where some participants (especially creationists) might
>>>>> not know you were being ironic?
>>>> Still yes.
>>> Well, I've crossposted this to talk.origins. Let's see whether the
>>> folks over there agree.
>> Agree with what? I don't really understand why you're posting this.
>Oh, that's clear enough. The Lord of Liars is attempting to open a second >front on his assault on jillery, and is doing as well as could be expected, >given his limitations.
Yeppers. The entire topic was thoroughly discussed and settled before
Rockhead tossed in his two bits. From that, it has devolved into
meaningless asides and irrelevant pedantic quibbling, a characteristic
common among topics featuring his participation.
> On Fri, 12 Oct 2012 10:37:22 -0400, "J.J. O'Shea"
> <try.not...@but.see.sig> wrote:
>> On Thu, 11 Oct 2012 23:25:51 -0400, John Harshman wrote
>> (in article <OZKdnWTMUfZdEOrNRVn_...@giganews.com>):
>>> On 10/11/12 7:49 PM, pnyikos wrote:
>>>> Revisiting a Science Daily article jillery posted about to
>>>> sci.bio.paleontology, I am struck by some strange language in it,
>>>> which might lead an unsophisticated reader to think that John Ruben
>>>> and Devon Quick, on the faculty of Oregon State University, had
>>>> serious doubts about common descent of tetrapods, let alone all
>>>> animals, let alone all life:
>>>> "We aren't suggesting that dinosaurs
>>>> and birds may not have had a common
>>>> ancestor somewhere in the distant past,"
>>>> Quick said. "That's quite possible and
>>>> is routinely found in evolution."
>>>> http://www.sciencedaily.com/releases/2009/06/090609092055.htm
>>>> But as several people, especially John Harshman, know, Ruben only
>>>> denies that birds are descended from dinosaurs.
>>> Why "especially"?
>>>> As an old-fashioned
>>>> systematist would say, he believes they are descended from thecodonts,
>>>> and Quick probably believes this too.
>>> Actually, Ruben never really says what he thinks. Dunno about Quick.
>>>> Now that this old-fashioned
>>>> language has been "discredited," awkward language such as the above
>>>> can be found all over the place.
>>> Please. Don't blame poor writing on cladistics.
>>>> Most of the article is about respiration in birds, and has Ruben and
>>>> Quick on a soapbox about their pet theory.
>>>> Back in sci.bio.paleontology, the discussion centered on certain
>>>> features of avian leg movement that enable deeper breathing by them.
>>>> On Oct 11, 11:20 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>> On 10/10/12 9:30 PM, pnyikos wrote:
>>>>>> On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>> On 10/5/12 10:38 AM, pnyikos wrote:
>>>>>>>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>>>> On 9/28/12 8:01 PM, pnyikos wrote:
>>>>>>>>>> On Sep 21, 11:36 am, John Harshman<jharsh...@pacbell.net>
>>>>>>>>>> wrote:
>>>>>>>>>>> jillery wrote:
>>>>>>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>>>>>>> they hold their hips more or less in place while rotating
>>>>>>>>>>>> their knees over a large angle.
>>>>>>>>>>> What you mean is that the femur rotates through a small angle and >>>>>>>>>>> the
>>>>>>>>>>> tibiotarsus through a large angle. And that's correct, for all >>>>>>>>>>> birds.
>>>>>>>> It seems pretty clear from the linked article that this is NOT what
>>>>>>>> the linked article meant, and so jillery probably did not mean it
>>>>>>>> either. The picture accompanying the linked article labeled both the
>>>>>>>> hip and the knee joints, using colors to highlight them.
>>>>>>> I fail to see how a hip joint can move. And the knee joint moves >>>>>>> exactly
>>>>>>> to the extent that the femur does.
>>>>>> Yeah, but jillery didn't use the word "moving" but rather "rotating"
>>>>>> in connection with the knee joint.
>>>>> Why should it matter what words jillery used? What should matter is what
>>>>> happens. What article meant, and what jillery presumably meant based on
>>>>> the article, was what I said.
>>>> Perhaps what you write is synonymous with what the article said, but
>>>> its actual words the article uses start out closer to those of jillery
>>>> than to yours:
>>>> During walking and running in birds,
>>>> hindlimb movement is generated primarily
>>>> at the knee and ankle joints; in humans,
>>>> movement occurs at the knee, ankle and hip joints.
>>> Only if you misunderstand what that sentence says, perhaps by >>> interpreting "at" to mean "by". To be excruciatingly clear: movement is >>> generated at a joint (at least the joints we're talking about) by >>> rotation in a parasagittal plane of the distal element. Movement at the >>> hip is movement of the femur; movement at the knee is movement of the >>> tibiotarsus; movement at the ankle is movement of the tarsometatarsus. >>> Ruben and Quick say exactly this, if you have the sense to read what >>> they say.
>> Well, Peter N _is_ the leading expert at arguing from false premises.
>>>> Only the last part of the caption says what you do, and only half of
>>>> it, and it seems clear that this all is due to the lack of mobility in
>>>> the hip joint:
>>>> The bird's thigh does not move substantially
>>>> from its nearly horizontal position where it
>>>> provides rigid lateral support to the thin walled
>>>> air-sacs of the respiratory system.
>>> I have no idea what you intend "lack of mobility in the hip joint" to >>> mean. I'm not sure you know what you mean, or what your point is.
>> His only point is to mount an unwarranted attack on someone much more >> honest >> than he is.
>>>> [snip of mostly s.b.p. shop talk, some of which will be replied to
>>>> there in a few minutes]
>>>>>>>>>>>> But theropod dinosaurs, from which birds are
>>>>>>>>>>>> supposed to have evolved, including velociraptors and >>>>>>>>>>>> Archaeopteryx,
>>>>>>>>>>>> didn't have this limitation, but stood with their knees >>>>>>>>>>>> more-or-less
>>>>>>>>>>>> straight, a very unavian posture.
>>>>>>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is >>>>>>>>>>> not >>>>>>>>>>> a
>>>>>>>>>>> bird.
>>>>>>>>>> I take it you are being ironic here.
>>>>>>>>> Good catch.
>>>>>> [snip]
>>>> [snip of mostly s.b.p. shop talk]
>>>>>>> Did you catch the ironic intent of "good catch"?
>>>>>> No. Are you suggesting that my observation was just too trivial to be
>>>>>> worth posting here?
>>>>> Yes. Good catch.
>>>> I suspect that you mean it this time.
>>> Your suspicions, as so often, are not warranted.
>> Of course not.
>>>>>> How about if this thread had been crossposted to
>>>>>> talk.origins, where some participants (especially creationists) might
>>>>>> not know you were being ironic?
>>>>> Still yes.
>>>> Well, I've crossposted this to talk.origins. Let's see whether the
>>>> folks over there agree.
>>> Agree with what? I don't really understand why you're posting this.
>> Oh, that's clear enough. The Lord of Liars is attempting to open a second >> front on his assault on jillery, and is doing as well as could be expected, >> given his limitations.
> Yeppers. The entire topic was thoroughly discussed and settled before
> Rockhead tossed in his two bits. From that, it has devolved into
> meaningless asides and irrelevant pedantic quibbling, a characteristic
> common among topics featuring his participation.
Does he _never_ tire of showing the world exactly what a slime he is?
On Oct 11, 11:20 am, John Harshman <jharsh...@pacbell.net> wrote:
[big snip]
> Archaeopteryx also,
> as far as I recall, has no metatarsal fusion. It's a later development
> in birds.
If I recall correctly, different specimens show different degrees of
fusion, from none to partial. Some speculate that the degree of fusion
is a function of ontogeny.
> On Fri, 12 Oct 2012 14:42:07 -0400, jillery wrote
> (in article<v2pg781ksf5ngdf87to6dt6q2vvprl1...@4ax.com>):
>> On Fri, 12 Oct 2012 10:37:22 -0400, "J.J. O'Shea"
>> <try.not...@but.see.sig> wrote:
>>> On Thu, 11 Oct 2012 23:25:51 -0400, John Harshman wrote
>>> (in article<OZKdnWTMUfZdEOrNRVn_...@giganews.com>):
>>>> On 10/11/12 7:49 PM, pnyikos wrote:
>>>>> Revisiting a Science Daily article jillery posted about to
>>>>> sci.bio.paleontology, I am struck by some strange language in it,
>>>>> which might lead an unsophisticated reader to think that John Ruben
>>>>> and Devon Quick, on the faculty of Oregon State University, had
>>>>> serious doubts about common descent of tetrapods, let alone all
>>>>> animals, let alone all life:
>>>>> "We aren't suggesting that dinosaurs
>>>>> and birds may not have had a common
>>>>> ancestor somewhere in the distant past,"
>>>>> Quick said. "That's quite possible and
>>>>> is routinely found in evolution."
>>>>> http://www.sciencedaily.com/releases/2009/06/090609092055.htm
>>>>> But as several people, especially John Harshman, know, Ruben only
>>>>> denies that birds are descended from dinosaurs.
>>>> Why "especially"?
>>>>> As an old-fashioned
>>>>> systematist would say, he believes they are descended from thecodonts,
>>>>> and Quick probably believes this too.
>>>> Actually, Ruben never really says what he thinks. Dunno about Quick.
>>>>> Now that this old-fashioned
>>>>> language has been "discredited," awkward language such as the above
>>>>> can be found all over the place.
>>>> Please. Don't blame poor writing on cladistics.
>>>>> Most of the article is about respiration in birds, and has Ruben and
>>>>> Quick on a soapbox about their pet theory.
>>>>> Back in sci.bio.paleontology, the discussion centered on certain
>>>>> features of avian leg movement that enable deeper breathing by them.
>>>>> On Oct 11, 11:20 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>> On 10/10/12 9:30 PM, pnyikos wrote:
>>>>>>> On Oct 5, 7:38 pm, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>>> On 10/5/12 10:38 AM, pnyikos wrote:
>>>>>>>>> On Sep 29, 12:50 am, John Harshman<jharsh...@pacbell.net> wrote:
>>>>>>>>>> On 9/28/12 8:01 PM, pnyikos wrote:
>>>>>>>>>>> On Sep 21, 11:36 am, John Harshman<jharsh...@pacbell.net>
>>>>>>>>>>> wrote:
>>>>>>>>>>>> jillery wrote:
>>>>>>>>>>>>> I freely admit most of this is new to me, that when birds walk,
>>>>>>>>>>>>> they hold their hips more or less in place while rotating
>>>>>>>>>>>>> their knees over a large angle.
>>>>>>>>>>>> What you mean is that the femur rotates through a small angle and
>>>>>>>>>>>> the
>>>>>>>>>>>> tibiotarsus through a large angle. And that's correct, for all
>>>>>>>>>>>> birds.
>>>>>>>>> It seems pretty clear from the linked article that this is NOT what
>>>>>>>>> the linked article meant, and so jillery probably did not mean it
>>>>>>>>> either. The picture accompanying the linked article labeled both the
>>>>>>>>> hip and the knee joints, using colors to highlight them.
>>>>>>>> I fail to see how a hip joint can move. And the knee joint moves
>>>>>>>> exactly
>>>>>>>> to the extent that the femur does.
>>>>>>> Yeah, but jillery didn't use the word "moving" but rather "rotating"
>>>>>>> in connection with the knee joint.
>>>>>> Why should it matter what words jillery used? What should matter is what
>>>>>> happens. What article meant, and what jillery presumably meant based on
>>>>>> the article, was what I said.
>>>>> Perhaps what you write is synonymous with what the article said, but
>>>>> its actual words the article uses start out closer to those of jillery
>>>>> than to yours:
>>>>> During walking and running in birds,
>>>>> hindlimb movement is generated primarily
>>>>> at the knee and ankle joints; in humans,
>>>>> movement occurs at the knee, ankle and hip joints.
>>>> Only if you misunderstand what that sentence says, perhaps by
>>>> interpreting "at" to mean "by". To be excruciatingly clear: movement is
>>>> generated at a joint (at least the joints we're talking about) by
>>>> rotation in a parasagittal plane of the distal element. Movement at the
>>>> hip is movement of the femur; movement at the knee is movement of the
>>>> tibiotarsus; movement at the ankle is movement of the tarsometatarsus.
>>>> Ruben and Quick say exactly this, if you have the sense to read what
>>>> they say.
>>> Well, Peter N _is_ the leading expert at arguing from false premises.
>>>>> Only the last part of the caption says what you do, and only half of
>>>>> it, and it seems clear that this all is due to the lack of mobility in
>>>>> the hip joint:
>>>>> The bird's thigh does not move substantially
>>>>> from its nearly horizontal position where it
>>>>> provides rigid lateral support to the thin walled
>>>>> air-sacs of the respiratory system.
>>>> I have no idea what you intend "lack of mobility in the hip joint" to
>>>> mean. I'm not sure you know what you mean, or what your point is.
>>> His only point is to mount an unwarranted attack on someone much more
>>> honest
>>> than he is.
>>>>> [snip of mostly s.b.p. shop talk, some of which will be replied to
>>>>> there in a few minutes]
>>>>>>>>>>>>> But theropod dinosaurs, from which birds are
>>>>>>>>>>>>> supposed to have evolved, including velociraptors and
>>>>>>>>>>>>> Archaeopteryx,
>>>>>>>>>>>>> didn't have this limitation, but stood with their knees
>>>>>>>>>>>>> more-or-less
>>>>>>>>>>>>> straight, a very unavian posture.
>>>>>>>>>>>> Which apparently demonstrates conclusively that Archaeopteryx is
>>>>>>>>>>>> not
>>>>>>>>>>>> a
>>>>>>>>>>>> bird.
>>>>>>>>>>> I take it you are being ironic here.
>>>>>>>>>> Good catch.
>>>>>>> [snip]
>>>>> [snip of mostly s.b.p. shop talk]
>>>>>>>> Did you catch the ironic intent of "good catch"?
>>>>>>> No. Are you suggesting that my observation was just too trivial to be
>>>>>>> worth posting here?
>>>>>> Yes. Good catch.
>>>>> I suspect that you mean it this time.
>>>> Your suspicions, as so often, are not warranted.
>>> Of course not.
>>>>>>> How about if this thread had been crossposted to
>>>>>>> talk.origins, where some participants (especially creationists) might
>>>>>>> not know you were being ironic?
>>>>>> Still yes.
>>>>> Well, I've crossposted this to talk.origins. Let's see whether the
>>>>> folks over there agree.
>>>> Agree with what? I don't really understand why you're posting this.
>>> Oh, that's clear enough. The Lord of Liars is attempting to open a second
>>> front on his assault on jillery, and is doing as well as could be expected,
>>> given his limitations.
>> Yeppers. The entire topic was thoroughly discussed and settled before
>> Rockhead tossed in his two bits. From that, it has devolved into
>> meaningless asides and irrelevant pedantic quibbling, a characteristic
>> common among topics featuring his participation.
> Does he _never_ tire of showing the world exactly what a slime he is?
Does it disturb you at all that you seem like a stalker?
> I freely admit most of this is new to me, that when birds walk, they
> hold their hips more or less in place while rotating their knees over
> a large angle. In contrast, most mammals move their hips over a much
> larger angle than do birds, even nonflying birds. Apparently even
> penguins stand in a kind of squat, with their thighs close to the
> abdomen and their knees bent.
> According to Quick and Ruben, this adaptation is necessary in order to
> support the posterior air sac during inspiration, that auxiliary
> structures like gastralia and uncinate processes don't prevent its
> paradoxical collapse. But theropod dinosaurs, from which birds are
> supposed to have evolved, including velociraptors and Archaeopteryx,
> didn't have this limitation, but stood with their knees more-or-less
> straight, a very unavian posture.
> So, assuming the above anatomical statements are correct, does that
> necessarily mean birds did not evolve from dinosaurs? Or that some
> dinosaurs evolved from birds? Isn't it plausible that this anatomical
> requirement became necessary after birds evolved powered flight? Is
> this a big question in the scientific community?
I am not a professional paleontologist. However, I have heard a few paleontologists talk on this. I don't have articles to reference. However, what I heard was this.
Almost surely, the basics of the avian respiratory system evolved before the birds evolved flight. The metabolic efficiency of the avian respiratory system would be just as useful for an animal running after it prey as for flying. The skeletons of some theropods, not all, are consistent with an avian type respiratory system.
The dinosaurs are unlikely to have developed the precise same respiratory system as birds, as they have different lifestyles. However, dinosaurs have a lot of the prerequisites for system like an avian system. Most dinosaurs had hollow bones filled with air. The air filled bones served in a number of ways. For instance, it lightened the bones in the larger dinosaurs. Large dinosaurs had bones that were reinforced at the joints where most of the stresses occurred. The hollow bones probably helped some dinosaurs swim through the buoyancy. The ancestors of the dinosaurs, such as thecondonts, were probably had to live in the water. That may be where the hollow bones first evolved. However, other features probably evolved later that took advantage of the hollow bones. Like many things in evolution, the different parts of the system may have evolved piecemeal but came together later for larger system. By the late Jurrassic, birds and thecodonts are barely distinguishable. It is very difficult to distinguish them.
There was always, from the beginning of dinosaur studies, this controversy as to whether dinosaurs were reptiles or birds. The fused clavicle, otherwise called the wishbone, was present in a few species of theropods.The absence of wishbones among dinosaur fossils was crucial in 1936 for the decision to classify dinosaurs as reptiles. However, dinosaur skeletons with wishbones were discovered in 1940. Many theropods were discovered to have wishbones. There was a recent discovery that dinosaurs had some dinosaurs had feathers and some had quills. The quills are important because they are not scales. The feather did not evolved directly from a scale, it evolved from quills.
I don't know how your sources know that femurs have to be held horizontally to protect the air sacs. I don't know how your sources know that dinosaurs didn't hold their femurs horizontally. I do know that there were to orders of dinosaurs which held their femurs differently. I suspect that your sources may be pointing at one group of dinosaurs that are more distantly related to birds than the other group.
There was not only more diversity among dinosaurs in the Mesozoic, there was more diversity among birds. I doubt that all dinosaurs, or even all birds, had the same type of respiratory system. My main problem is picturing what you mean by "air sacs collapsing". Furthermore, I don't know where in the dinosaurs body the air sacs were. Maybe the air sacs were in the forearms, which were generally held horizontally.
I am not saying that you are wrong in what you are saying. I am saying that I never heard the claim that dinosaurs were that different from birds that they could never use air sacs in their bodies the way birds use air sacs. BTW: The museums in New Mexico there also like to show models of the road runner next to models of the Rioaribosaurus (previously, Coelophysis), their state dinosaur. Road runners are all over the state, so one could at least verify that their models of road runners was accurate.
The stance of the two animals was very similar, at least the way these museum showed it. There didn't seem to be a significant difference in the way the road runner runs and the Rioaribosaurus ran. Rioaribosaurus had a more substantial tail, of course. However, both were very predators.
Road runners are a little more aggressive than is shown in the cartoon. These guys hunt rattlesnakes for lunch. They fly a little (like chickens) but their main hunting techniques involve fast motions on the ground. They fly only to get away from enemies. This is one technique you never see used on coyote.
It seems to me that road runner femurs aren't quite horizontal as you say. However, I may be wrong.
