Bird breathing anatomy breaks dino-to-bird dogma
by Jonathan Sarfati
Photo by Steve Murray
Bird feet (red-footed booby)
Published: 16 June 2009(GMT+10)
Do we eat Kentucky Fried Dinosaur? According to the dogma of many evolutionary propagandists
for the last decade or so, indeed we do—they believe that birds evolved from
the carnivorous dinosaur group known as theropods. Yet there are many problems with
this idea. And now, new research into the birds’ lung and leg anatomy provides
more strong evidence against it.
Dinosaurs living today—in trees?
The BBC program Walking with
Dinosaurs proclaimed that we can see and hear dinosaurs outside our
windows. Many museums have proclaimed the dinosaur origin of birds as fact, such
as the
Australian Museum in Sydney and
Queensland Museum in Australia.
National Geographic was so gung-ho for this idea that they promoted Archaeoraptor,
which turned out to be a
“Piltdown Bird” forcing an embarrassing retraction.
Evolutionary dissent
However, there have been some lonely dissenters even among evolutionists. For example,
Dr Storrs Olson, Curator of Birds at the National Museum of Natural History of the
Smithsonian Institution in Washington, D.C. wrote a
scathing open letter about National Geographic’s Archaeoraptor:
“The idea of feathered dinosaurs and the theropod origin of birds is being
actively promulgated by a cadre of zealous scientists acting in
concert with certain editors at Nature and National Geographic
who themselves have become outspoken and highly biased proselytizers of the
faith.”
Another skeptic is Dr Alan Feduccia, a world authority on birds at
the University of North Carolina at Chapel Hill, who criticized the dogma on anatomical
grounds:
“It’s biophysically impossible to evolve flight from such large bipeds
with foreshortened forelimbs and heavy, balancing tails,’ exactly the wrong
anatomy for flight.”1
So the ‘earliest’ bird had the through-flow avian lung system, while
one of its closest ‘ancestors’ had a reptilian bellows lung. The transitional forms
are lacking.
And he criticized it on chronological grounds too. The alleged “ancestors”
for birds are “dated” (by evolutionary methods) as millions of years
younger than the birds. E.g., claimed “feathered dinosaur ancestors”
Sinosauropteryx and Caudipteryx are “dated” at 125
Ma (million years old), which is 28 Ma younger than the first undoubted
bird Archaeopteryx (153 Ma)
and even about 10 Ma younger than the beaked bird
Confuciusornis (135 Ma)! As Feduccia quips, you can’t be
older than your grandfather! Dino-bird believers respond that sometimes a grandfather
can outlive his grandson. But while correct, it’s hard to understand that
an “advanced” beaked bird like Confuciusornis could appear
10 million years before there is a trace of its “feathered dino ancestors”.
Also, one of the major ‘evidences’ of evolution is how the evolutionary
order supposedly matches the fossil sequence. Therefore the gross mismatch with
the dino-birds is a severe challenge to the evolutionary explanation.
Avian lung design
Yet another problem for the dino-bird theory is that birds and reptiles have very
different lung systems. Reptilian lungs operate like bellows (like our own lungs,
although the reptile lung structure is different). The stale air is then breathed
out the same way it came in. But birds have a complicated system of air sacs, even
involving their hollow bones. This system keeps air flowing in one direction
through special tubes (parabronchi, singular parabronchus) in
the lung, and blood moves through the lung’s blood vessels in the opposite
direction for efficient oxygen uptake,2
an excellent engineering design.3
(See also Blown away by design,
and the Avian
Lung from Refuting Evolution ch. 4).
Recent research has shown that Archaeopteryx skeletons had pneumatized
vertebrae and pelvis. This indicates the presence of both a cervical and abdominal
air sac, i.e. at least two of the five sacs present in modern birds. This in turn
indicates that the unique avian lung design
was already present in what most evolutionists claim is the earliest bird.4
Conversely, alleged feathered
dinosaur Sinosauropteryx was found so well fossilized that the outlines
of some internal organs could be analysed. The lead researcher Dr John Ruben, a
respiratory physiology expert at Oregon State University in Corvallis, concluded5 that its
“bellowslike lungs could not have evolved into the high-performance
lungs of modern birds.”6
So the “earliest” bird had the through-flow avian lung system, while
one of its closest “ancestors” had a reptilian bellows lung. The transitional forms
are lacking.
Ruben noted the problem for the dino-bird theory in general: how would the ‘bellows’-style
lungs of reptiles evolve gradually into avian lungs? The hypothetical intermediate
stages could not conceivably function properly, meaning the poor animal would be
unable to breathe. One of the first stages would be a poor creature with a diaphragmatic
hernia (hole in the diaphragm), and natural selection would work against
this. Ruben writes:
“The earliest stages in the derivation of the avian abdominal airsac system
from a diaphragmatic-ventilating ancestor would have necessitated selection for
a diaphragmatic hernia [i.e. hole] in taxa transitional between theropods and birds.
“Such a debilitating condition would have immediately compromised the entire
pulmonary ventilatory apparatus and seems unlikely to have been of any selective
advantage.”
New discovery: fixed thigh bone is vital for breathing
Theropod dinosaurs had a moving femur and therefore could not have had a lung that
worked like that in birds. Their abdominal air sac, if they had one, would have
collapsed. That undercuts a critical piece of supporting evidence for the dinosaur-bird
link.—John Ruben
Dr Ruben has continued his research into bird breathing. Recently, he and his OSU
colleague Dr Devon Quick “made a fundamental new discovery about how birds
breathe and have a lung capacity that allows for flight — and the finding
means it’s unlikely that birds descended from any known theropod dinosaurs.”7
It has long been known that birds have a fixed femur (thigh bone), so they are “knee
runners”. Mammals and reptiles—including dinosaurs—have movable
femurs that are highly involved in their walking and running. But why do birds have
this unusual arrangement?
Quick and Ruben found that this fixed femur and the accompanying muscles and hip
bones were essential for the bird to keep its air-sac lung from collapsing inwards
when the bird inhales.8
Quick said:
“This is fundamental to bird physiology. It’s really strange that no
one realized this before. The position of the thigh bone and muscles in birds is
critical to their lung function, which in turn is what gives them enough lung capacity
for flight.”7
But since the theropods had moving femurs, they could not have supported the air
sacs needed for the avian lung system. According to a report:
“‘For one thing, birds are found earlier in the fossil record than the dinosaurs they are supposed to have descended from,’ Ruben said. ‘That’s a pretty serious problem, and there are other inconsistencies with the bird-from-dinosaur theories.
‘But one of the primary reasons many scientists kept pointing to birds as having descended from dinosaurs was similarities in their lungs,’ Ruben said. ‘However, theropod dinosaurs had a moving femur and therefore could not have had a lung that worked like that in birds. Their abdominal air sac, if they had one, would have collapsed. That undercuts a critical piece of supporting evidence for the dinosaur-bird link.
“A velociraptor did not just sprout feathers at some point and fly off into
the sunset.”7
Frankly, there’s a lot of museum politics involved in this, a lot of careers
committed to a particular point of view even if new scientific evidence raises questions.—John
Ruben
Ruben has long been sceptical of the dino-to-bird dogma, even from the 1990s. Yet
he notes:
“Frankly, there’s a lot of museum politics involved in this, a lot of
careers committed to a particular point of view even if new scientific evidence
raises questions.”7
He pointed out that many museum displays treat the dino-to-bird theory as fact,
just as we noted above. The only nod to dissent might be an
asterisk with some fine print saying, “some scientists disagree.” But
now Ruben says, “But now there are more asterisks all the time. That’s
part of the process of science.”7
Evolutionary dogma
Photo: Don Batten
Sinosauropteryx prima
Despite their rejection of dino-to-bird dogma, both Ruben and Quick, like Feduccia,
believe that birds evolved from some sort of reptile. But here they become tentative,
e.g. Quick says:
“We aren’t suggesting that dinosaurs and birds may not have had a common
ancestor somewhere in the distant past. That’s quite possible and is routinely
found in evolution. It just seems pretty clear now that birds were evolving all
along on their own and did not descend directly from the theropod dinosaurs, which
lived many millions of years later.”
But an evolutionary criticism of Feduccia and his supporters applies equally well
to Ruben and Quick:
“Neither their hypothetical ancestor nor transitional forms linking it to
known fossil birds have been found. And although they rightly argue that cladistic
analyses [comparisons of shared characteristics] are only as good as the data upon
which they are based, no cladistic study has yet suggested a non-theropod ancestor.”9
Most scientists believe in evolution not because of the evidence, but because most
scientists believe it.
But goo-to-you evolution in general, not just the dino-to-bird theory, has become
a dogma. Most scientists believe in evolution not because of the evidence, but because
most scientists believe it. I.e. the oft-touted consensus on evolution was reached
by counting heads that themselves came to this consensus by counting heads. And
when asked to provide evidence, many cannot make a good case—e.g. Feduccia’s
best “proof” of evolution was not in his field of ornithology, but corn turning into
corn!
There is another alternative: Ruben, Quick and Feduccia are right that birds didn’t
evolve from theropods; their evolutionary detractors are right that birds didn’t
evolve from non-theropod reptiles. Rather, they did not evolve at all!
Related articles
Further reading
Related resources
References
- Gibbons, A., New Feathered Fossil Brings Dinosaurs and Birds
Closer, Science 274:720–721, 1996.
Return to text.
- Denton, M., Evolution, a Theory in Crisis, pp. 199–213,
Adler & Adler, Bethesda, MD, 1986; K. Schmidt-Nielsen, How Birds Breathe, Scientific
American, pp. 72–79, December 1971. Return to text.
- Engineers make much use of this principle of counter-current
exchange which is common in living organisms as well—see P.F. Scholander,
The Wonderful Net, Scientific American 196:96–107,
April 1957. Return to text.
- Christiansen, P. and Bonde, N., Axial and appendicular pneumaticity
in Archaeopteryx, Proceedings of the Royal Society of London, Series B.267:2501–2505,
2000. Return to text.
- Ruben, J.A., et al.,
Lung structure and ventilation in theropod dinosaurs and early birds, Science
278(5341):1267–1270, 1997. Return to text.
- Ruben, quoted in Ann Gibbons, Lung Fossils Suggest Dinos Breathed
in Cold Blood, Science 278(5341):1229–1230, 14 November
1997. Return to text.
-
Discovery raises new doubts about dinosaur-bird links, ScienceDaily.com,
9 June 2009. Return to text.
- Quick, D.E. and Ruben, J.A., Cardio-pulmonary anatomy in theropod
dinosaurs: Implications from extant archosaurs, Journal of Morphology, 20
May 2009 | DOI:10.1002/jmor.10752.
“The thin walled and voluminous abdominal air-sacs are supported laterally
and caudally to prevent inward (paradoxical) collapse during generation of negative
(inhalatory) pressure: the synsacrum, posteriorly directed, laterally open pubes
and specialized femoral-thigh complex provide requisite support and largely prevent
inhalatory collapse.” Return to text.
- Shipman, P., Birds Do It … Did Dinosaurs? New Scientist
153(2067):26–31, 1997, p. 28. Return to text.
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