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Emily A. Willoughby
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Interesting to see that as of writing this, this book has nothing but 1-star and 5-star reviews. I hope that my review can offer a slightly different perspective.
As others have pointed out, Feduccia's primary arguments rest on ridiculous assumptions, completely unsupported reinterpretations of data, and to be frank, basically devolve into petulant whining and vitriol in the latter parts of the book. This has been discussed in detail by reviewer Herman Diaz above, so I won't rehash his points unnecessarily here. Instead I'll focus on the aspects of the book that prevented me from giving it the lowest review score possible.
Early in the book, Feduccia makes some legitimate points that I think should be carefully and unemotionally considered by the scientific community. It absolutely is the case that journals have a bias for what kind of research they accept. Feathered dinosaur-related research is very mainstream right now, and the media and the general public just eat it up. Journals and institutions love the financial support and attention this kind of publication incurs, and so I do not doubt that they are more keen on publishing research that supports the dinosaur-bird connection.
And by the same process, I also don't think it's surprising that journals are less willing to publish research that may result in conclusions that go against the dinosaur-bird dogma: it's less talked about, and less considered, and less interesting to the public. I also think Feduccia is correct in his assessment that the true evolutionary origin of birds is still somewhat shrouded in mystery - in the details, at least. The evidence at this point in time firmly indicates that birds diverged from coelurosaurian dinosaurs, but when? Where? Ground-up or trees down or somewhere in between? From gliders, or from animals who had nothing to do with gliding? Through media representation of research, the general public has adopted the idea that the question of bird evolution and the evolution of flight is completely solved, open-and-shut, when in reality it couldn't be further from the truth. For instance, there is an Triassic trackway from Argentina that, from all appearances, seems to be of bird tracks with fully-reversed halluces. The only follow-up study (Genise et al 2009) done on this ichnotaxon seems to indicate that the tracks involved evidence of takeoff and landing, which further supports the idea that these were definitely birds. While this seems to be (unfortunately) a popular line of evidence among BANDits (and creationists, sadly), there is no mainstream explanation for how these tracks exist other than a vague and unsatisfactory "the age needs to be established with more certainty before we can conclude anything." But rather than do additional studies and research into analyzing this trackway which could be really interesting, mainstream paleontologists seem to have basically forgotten about it.
Along a similar vein, Kenneth Carpenter (1997) has pointed out evidence of Gorgosaurus scale imprints that have been known for at least twenty years, but have never been formally published. Research can of course take many years to publish for a myriad of reasons, but it seems highly likely that had these imprints been of feathers, they'd been published almost immediately. It seems like there is something fundamentally wrong with a system that more readily publishes research that is exciting and interesting because it conforms so smoothly with the dominant paradigm, when conflicting research that challenges some of these established lines of thinking might ultimately result in a more robust and less flawed theory overall.
Feduccia also repeatedly criticizes the practice of cladistics throughout the book, and indeed all of his theories more or less necessitate the invalidation of cladistics, since they completely fly in the face of the current understanding of birds being nestled within maniraptorans. Again, this is a wasted opportunity. There are, I think, some reasonable critiques that can be made of cladistics, since its reliability is completely dependent on a number of subjective interpretations: which characters are worth including, whether each character is truly present or absent, which organisms are included; it also cannot take into account convergence or reversals. But imperfect though it may be, cladistics is ultimately self-correcting, given enough time, enough material, enough organisms and enough revisions, and most importantly, it's the best logical system we currently have for establishing relationships among extinct animals (when used alongside common sense, and when knowing its limitations). Feduccia does not seek to present a consistent alternative to cladistics, nor does he seek to address with any degree of specificity what particular mathematical or anatomical errors are committed in cladistics repeatedly assigning birds to be a nestled group of dinosaurs.
I think Feduccia is a brave guy for bringing up these uncomfortable ideas, a sparse few of which I believe do genuinely deserve a second look. Unfortunately, he also seems to be pretty misguided, likely too incensed by his emotional attachment to his BAND ideals to objectively look at the evidence, which is so much more voluminous than it was thirty years ago or whenever he started writing about this (when it was still a valid alternative hypothesis). Nevertheless, it's really too bad that we don't tend to see this kind of criticism on journal bias and the blind adherence to cladistics outside of "fringe" ideas like BAND. I think these are legitimate issues, and I wish that more "mainstream" scientists would take a look at them, but no one besides the fringers really seem to care. I think that non-BANDit paleontologists have become almost sort of afraid of researching anything that might not fit neatly inside of the current birds-are-dinosaurs thinking, lest others think they're secret BAND supporters, or unwittingly lending them more credibility than they deserve. In reality, the opposite should be the case: every piece of conflicting research, if carefully crafted, should only serve to strengthen a sound theory in the end.
Anyway, my main point is: I don't think BAND is entirely crazy, I just think they're maybe 90% crazy. But they are not crazy on the same level as creationists, and while I certainly understand and sympathize with mainstream paleontologists for how annoying and dishonest they can be, I also think it's too bad that no one seems to really be making an effort to take seriously the valuable things BANDits have to say, while discarding the crap.
13 de 22 personas piensan que la opinión es útil
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I have always been interested in the dinosaur-bird controversy, even though I have not worked on any of the relevant areas of paleontology. My passion for the subject comes from many sources, including the following:- 1. An early champion of the dino-bird connection, Thomas Henry Huxley was a personal hero who became famous for his eloquent discourse on the subject, who married an Australian wife, and who probably shared my bipolar diathesis; 2. I once caught a flight to Sydney to see the famous feathered dinosaurs on display at the Australian Museum, which I discovered were not unequivocally feathered at all!; 3. I acquired an intimate knowledge of the sensory physiology of birds with which I share an empathy that has encouraged in me a strong motivation to learn more about their origins; 4. I have painful personal experience with the unsavoury tactics of antagonists in another phylogenetic controversy, the flying primate debate, which shares overlapping polemicists and tricksters with the avian origins debate, both of which debates, inter alia, concern the evolution of vertebrate flight.
There are other reasons that I could recount too, but the point is to introduce Alan Feduccia's new book on the topic, "Riddle of the Feathered Dragons", which I was impatient to read. Feduccia's first book on this subject, "Origin and Evolution of Birds" was reviewed simultaneously in both of the top scientific journals, Nature and Science, in 1981 when it stretched credulity, on reading these two contrasting reviews, that they concerned the same book! The Nature review by Mark Norell and Luis Chiappe was a savage attack from two dyed-in-the wool, hot-headed antagonists, while the Science review by Kenneth Campbell was a balanced account whose major criticism concerned the quality of the illustrations. This criticism applies also to the new book, whose half-tones are a bit fuzzy on matte paper, but it has to be pointed out that Feduccia gives details of the provenance of each illustration so that an interested reader can source the original, a politeness that is rare in books these days. As Campbell pointed out in his review of the previous book, it is Feduccia's prose that makes this book worthwhile. Feduccia has an incisive style that makes it clear where he stands. He is also polite to those on the other side of the controversy, albeit giving them plenty of rope to hang themselves where appropriate. This politeness contrasts markedly with the ill-considered polemics of his many antagonists which can readily be sampled on the internet.
Feduccia is a member of the "loyal opposition", who along with Larry Martin, have not been swayed by the mountain of studies that put forward the thesis that birds are theropod dinosaurs. The book sets out a number of points that form the basis of the "loyal opposition" to the theropod dinosaur-bird link. These points have not been adequately tested, if at all, by the opposition. They are summarised below:-
1. Life forms share basically the same DNA molecule, so we are all linked toward the base of the tree of life. For this reason it is obvious that birds and dinosaurs must have had a common ancestor at some earlier point, but was it a theropod dinosaur? And so late in the Mesozoic? With that in mind, Feduccia carefully sets out much of what is known about the fossil ancestors of dinosaurs and birds so that it is possible to avoid the facile trap of placing excessive weight on the linkage that any two lineages must have had at some time in the past.
2. Another major point concerns one's definition of a bird, a key issue in the first book. Feduccia has always maintained that birds are defined by their feathers, those unmistakeable and beautiful specialisations of the integument, with unique structures like rachis and barb, that bear no obvious relation to the collagenous filaments on the inside of the integument in a variety of Mesozoic vertebrates that have also been called "feathers". This was the unconvincing "fuzz" that I saw on my trip to see "feathered dinosaurs" at the Australian Museum's display of Liaoning fossils. Fuzz of this kind has also been described in completely unrelated pterosaurs and ornithiscian dinosaurs. Martin and Feduccia both have an uncomplicated viewpoint that fossils with feathers are birds (perhaps flightless ones, as dealt with below).
3. Another point concerns the polarity of evolution, which Feduccia discusses in the context of flightlessness in birds, for which there are no known examples of reversals, despite the very common occurrence of flightlessness in recent birds, and most likely, in Mesozoic birds too.
Polarity is the bugbear of many phylogenetic analyses and there are published phylogenies, both molecular and morphological, which are upside down because polarity was determined for the data matrix by reference to an inappropriate outgroup. [A moment's consideration will show that forcing an outgroup to the base of the tree, as these analyses usually do, will "pull" taxa with more derived characters there too, so inverting the order of steps in the tree, if the chosen "outgroup" is actually part of the ingroup, with many derived characters]. As Feduccia points out, polarity must ultimately be determined from the relative age of the various fossils of supposed progenitors, so the current almost-religious reliance on cladistic analyses of data matrices has a circularity that needs to be broken by the appropriate detailed considerations of relative timing that are available from natural history, such as Feduccia's apt generalisation that avian flightlessness is common now, was probably equally common in the Mesozoic, and has never reversed as far as we know.
4. If Feduccia is right, that Mesozoic flightless birds are masquerading as theropods, perhaps quantitative studies could be brought to bear on this. To take just one example, one distinguishing feature of birds and theropods is the marked forelimb foreshortening of the latter, so it might be possible to differentiate Mesozoic flightless birds quantitatively on the basis of a consideration of progressive foreshortening of their forelimbs at the same time as one tries to determine the polarity of such changes.There is no reason to think that all birds failed to evolve flightlessness in the Mesozoic, when they had much more time to do so, around 100 million years of the Mesozoic compared with 65 million years of the more recent times when there are abundant examples of terrestrial flightless birds. As well as having plenty of time, they were also more diverse, with two great lineages, the Enantiornithes having died out at the end of the Cretaceous. It might be argued that Neornithes exhibited more evolutionary plasticity than their extinct enantiornithine cousins from the Mesozoic, and so more cases of recent flightlessness. Even if one could sustain this argument, Neornithes have an ancient record from both fossil and molecular evidence that raises the question of why there is, thus far, no evidence that flightlessness has appeared during a period that is more than twice the length of the recent time when flightlessness has evolved many times over, never reversing. Rails lose the power of flight at the drop of a hat, by virtue of small, delaying, adjustments of the embryonic development of the flight apparatus, which is late in rails. This emphasises the ease with which birds can divest themselves of flight and gives added emphasis to Feduccia's hypothesis.
5. A logical point from physics emphasised by Feduccia impinges on the controversy, although many would consider its inclusion as too global to be relevant to the interpretation of fossil birds and dinosaurs. For me it is a crucial point, and one that also rears its head in the flying primate debate. A logical conclusion that follows acceptance of the dino-bird link is that the evolution of flight is ground-up rather than trees down. I have always regarded the ground-up scenario for the evolution of flight as physically implausible. The innumerable examples of the evolution of gliding flight in extant vertebrates (excluding the contentious birds, there are around a dozen independent examples), all fit the trees-down scenario. Since the ground-up scenario cannot be separated from the dino-bird hypothesis, Feduccia and I agree that one should look very critically at a hypothesis when the contextual implications contradict physics.
For an outsider, the most difficult aspect of the book is the plethora of new names for Mesozoic taxa with which one has to become a little familiar if one is truly to master Feduccia's thesis. Thankfully, there is a comprehensive index so that one can refresh one's memory about the later mention of an unfamiliar taxon, such as a troodontid or a scansoriopterygid, by finding its illustration or earlier mention. As one tries to master the wealth of new detail that has been provided on Mesozoic birds and dinosaurs that Feduccia is obviously in touch with, one realises that it takes an unusual human brain to get on top of all the details yet be able to entertain a variety of global evolutionary permutations of them. Such human cerebral limitations may partly explain the popularity of the many computer algorithms for phylogenetic reconstruction. Despite the convenience of these algorithms in systematising very large data matrices that few human minds have the motivation and capacity to handle, they have flaws, some of which are detailed by Feduccia. High on his list is convergence, a major source of difficulty in phylogenetic reconstruction. Convergence would be expected to constrain the evolution of two unrelated terrestrial bipeds in the same direction so that they came to share derived skeletal traits that might be misinterpreted as relatedness. The possibility of convergence casts doubt over even the massive skeletal data matrix that appears to support the bird-dinosaur link. Convergence is pervasive in evolution and requires sensitive techniques for its detection, which may take many years after the first false alignment of two taxa, like the New World and Old World vultures or the Doppler-shift compensation strategy for acoustically hunting for insects in clutter independently discovered by New World pteronotid and Old World rhinolophoid microbats. Even DNA molecules themselves can be subject to convergence, as shown early on by Allan Wilson and recently by Bernardi's demonstration of the effects of body temperature. This has led to many cases where false, even preposterous, pairings persisted despite huge amounts of DNA sequence data. The essential feature of convergence is that two taxa appear to be much closer phylogenetically than when the distance between them is calculated indirectly using other methods such as the distances to nearby taxa. There are now quantitative techniques that can "crack" convergence by measuring evolutionary distance between candidate taxa in two different ways to reveal the discrepancy between them that is diagnostic of convergence. Such techniques do not yet seem to have been applied to the dino-bird controversy, although I have always felt that the cladistic case for the dinosaur-bird link from skeletal characters was flawed because of the likelihood of convergence, which was ignored and certainly not tested for, except in a superficial, circular, way using parsimony.
There is another potential flaw in the use of large data matrices to replace reasoning and the presentation of the raw material. I hate to mention this, having encountered it in the course of the flying primate debate on the possibility that mammalian powered flight has evolved twice. This is currently a minority viewpoint like Feduccia's trees-down hypothesis for bird flight. It is relatively easy to "salt" a large data matrix with manufactured character states that support one's side of the controversy if there is a small risk of a referee knowing, or being able to go back to, the original material. As the late Hendrik van der Loos used to point out, it is easier to detect such malfeisance if one is used to "peeing in the same corner". In the case that I was involved in, these were not random or typographical errors in the data matrix, but systematic changes that all falsely supported the hypothesis of bat monophyly being pushed by the authors. I have no idea whether this has also happened in the somewhat acrimonious phases of the dino-bird debate, but I note a degree of overlap between the casts of characters in both these debates that involve evolution of flight, as well as noting the scoundrel reputation of American paleontologists that has come down to us from Cope and Marshall.
Alan Feduccia reminds me of Alfred Wegener, whose minority position on continental drift was the subject of bitter taunts and exclusion by his geological colleagues. Opinions reversed almost overnight when magnetometer traverses of the ocean basins revealed the zebra stripes of sea floor spreading. The student's insight to use the reversing of the earth's magnetic field to check the ocean floor was too late to turn around Wegener's detractors before he died, but perhaps there is a similar bright idea on birds and dinosaurs around the corner that could distil Feduccia's erudition and global grasp of the many disparate facts into a key observation capable of flipping the current consensus in the same way that caused most to change sides over continental drift.
Feduccia provides personal pictures of many of the dino-bird protagonists, placing them with their academic details and acting as a voice for their quotations, which are variously astonishing in their arrogance, or prescience, or insight . He is very fair in this, considering the ad hominem flak that he has personally had to endure over the years. He is, or was, friends with many on the other side of the controversy, like the late John Ostrom, whose ground-up hypothesis for the evolution of bird flight has perhaps added more fuel and acolytes to it than have all the bones and feathers combined, and who is affectionately portrayed. Among the quotations are some that will surprise even those with the slightest interest in science, unless they happen to be creationsists. Take this one for instance.:-Some protagonists of the bird-dino thesis have complained that antagonists, like Feduccia, have refused to desist in their efforts after failing to dislodge the thesis from its dominant perch after 20 years of trying! They wish. The history of science is littered with examples of dogma that persisted for many times this short period before being overturned, one example being Alfred Wegener's proposal of continental drift that I already mentioned. This complaint is an admission by the dino-bird advocates that they are championing dogma. Perhaps this book will serve to stimulate more challenges of that dogma from bright young students like the originator of the magnetometer traverse for sea floor spreading.