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Monday, June 04, 2007

Did Dinosaurs Have Feathers?

 
An article on the National Geographic website addresses an issue in the evolution of birds ["Feathered" Dinosaur Was Bald, Not Bird Ancestor, Controversial Study Says].

The article deals with a recent report by a group at the University of KwaZulu-Natal in South Africa; University of North Carolina (Chapel Hill); and the Chinese Academy of Sciences, in Beijing. The paper was published in the journal Proceedings of the Royal Society B. The authors claim that the "feathers" seen on recent dinosaur fossils are not feathers at all but collagen fibers. This is a minority opinion and the reason why I mention the article is to point out how good science writing can put things in context. Here's an example,
Lingham-Soliar and colleagues' results support the arguments of a small but highly vocal group of scientists who say there's no evidence of dinosaurs ever having feathers.

"The existence of protofeathers in these dinosaurs was considered critical evidence that birds were derived from dinosaurs," said study co-author Alan Feduccia, a bird evolution expert at the University of North Carolina at Chapel Hill.

"What we have shown is that there's absolutely no evidence whatsoever that protofeathers existed in dinosaurs, period."

But the majority of scientists in the field are unconvinced.
The article then goes on to quote from a number of scientists who disagree with the findings of the South African group.
"These people have been flogging the same horse for a long time," said Kevin Padian, curator of the University of California Museum of Paleontology.

"It is appalling that Proceedings B chose to publish this nonsense."
We need more of this kind of reporting.

Lingham-Soliar, T., Feduccia, A., and Wang, X. (2007) A new Chinese specimen indicates that ‘protofeathers’ in the Early Cretaceous theropod dinosaur Sinosauropteryx are degraded collagen fibres. Proc. Roy. Soc. B: published online Wednesday, May 23, 2007

6 comments :

  1. Why do we need more of that kind of reporting?

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  2. This is quite interesting, and I agree the reporting is pretty good, too. It's apparently a contentious issue, with a "small but highly vocal group" in opposition to a larger number of other scientists.

    I think the National Geographic Society presented this rather well, showing both sides, and a few good comments from a self-proclaimed "neutral".

    The kicker for me, that decided my mind in favour of the birds-are-dinosaurs hypothesis and against the others, was on the second page:

    Feduccia, the study co-author, says these creatures are actually descendants of birds that lost their ability to fly....
    "We are dealing here basically with a faith-based science where the contrarian view is silenced to a large extent by the popular press," he added.


    I should still read the Proc R Soc B paper anyways, but an appeal to the popular press is a dead giveaway that the science probably isn't really there. The hypothesis that birds are not descended from dinosaurs was published in Proc R Soc B, a very well respected and high-impact journal. How does that indicate a constraining role by "the popular press"?

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  3. Feduccia:

    "The existence of protofeathers in these dinosaurs was considered critical evidence that birds were derived from dinosaurs,"

    That statement by Feduccia is rubbish. The dinosaurian origin of birds is supported by a host of phylogenetic analyses going back to, at least, Gauthiar in 1986. The first feathered non-avian therapods didn't start arriving on the scene until over 10 years later. Feathered non-avian therapods are the icing on the cake not the "critical evidence".

    Just one reason why Kevin Padian considers this "nonsense".

    GAUTHIER, J.A. (1986) - Saurischian monophyly and the origin of birds, in PADIAN, K. (Ed.), The Origin of Birds and the Evolution of Flight. Mem. Calif. Acad. Sci., 8: 1-40.

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  4. Why do we need more of that kind of reporting?

    Because "he said, she said" reporting is a mjor contributor to people not understanding issues, in science, in politics, pretty much anywhere. There are some times when there are genuine controversies with apparently equal evidence, but much reporting nowadays takes things where one side has loads of evidence and the other side has little or none (or contrary evidence) and treats them as if they were both equally likely.

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  5. Feduccia is a pompous ass. Glad to see it stated plainly as this.

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