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Post by creature386 on Aug 18, 2015 23:50:12 GMT 5
This a thread similar to my last thread about creationism (ironically, creationists love to cite BANDits, as they argue against the current paradigm on bird evolution). I know that BANDits (Birds Are Not Dinosaurs) have significantly less arguments than creationists, but we can maybe discuss certain claims in greater detail here. I start (note that the rebuttals here are not exactly very detailed, this is only to have something to begin with). Claim 1: Caudipteryx was a bird rather than a dinosaur. In the light of problems associated with theories (1) and (2), perhaps the third, that Caudipteryx was a secondarily flightless, post-Archaeopteryx, cursorial bird, deserves closer scrutiny than it has received so far. We find it a striking coincidence that the only unambiguously feathered theropod was also the only known theropod likely to have utilized locomotory mechanisms identical to those of cursorial birds. (Click for the source)1. The analysis relies on too many a priori assumptions. You won't get the results without them (Dyke and Norell, 2005). 2. Cursoriality in birds developed several times independently (Mitchell et al., 2014). Hence, it is maybe not the best basis to classify Caudipteryx as a bird. 3. Ji et al. (200) based their phylogenetic analysis on 90 characters of which three are unambiguous. BANDits have so far not produced a better analysis Dyke, G.J. and Norell, M.A. 2005. Caudipteryx as a non−avialan theropod rather than a flightless bird. Acta Palaeontologica Polonica 50 (1): 101–116. (click for source)Mitchell, K.J. et al. 2014. Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution. Science 334 (6186): 898-900Ji, Q.; Currie, P.J.; Norell, M.A.; Ji, S. (1998). Two feathered dinosaurs from northeastern China. Nature 393 (6687): 753–761Claim 2: Dinosaur protofeathers were collagen. Rather, based on histological studies of the integument of modern reptiles, which show complex patterns of the collagen fibers of the dermis, we conclude that “protofeathers” are probably the remains of collagenous fiber “meshworks” that reinforced the dinosaur integument. (again clickable)1. This might explain some, but not all dinosaur feather impressions. For instance Microraptor gui impressions even show feathered wings. 2. There are examples of dinosaur integument which defy the collagen theory with their elongated and hollow nature (Zheng et al., 2009). 3. The distribution over the body and proximity to the vertebra of most of these structures is more consistent with the integument than the collagen hypothesis (Schweitzer 2011). Xiao-Ting Zheng, Hai-Lu You, Xing Xu & Zhi-Ming Dong. (2009) An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures. Nature 458 (19): 333-336Schweitzer, MH. (2011) Soft Tissue Preservation in Terrestrial Mesozoic Vertebrates. Annual Review of Earth and Planetary Sciences 39: 187-216 |
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Post by creature386 on Aug 24, 2015 16:40:12 GMT 5
Some more input: a) The digits of birds and dinosaurs are radically different (I have no particular source for this, but this is a common claim). 1. Addressed in detail in my creationism thread: theworldofanimals.proboards.com/post/24112/threadb) (no quote, summary) Supporters of the integument theory pointed out that they found melanosomes in Sinosauropteryx's structures which invalidate the collagen theory as collagen lacks such melanosomes. However, the scientific study that claimed to have found them should be seriously questioned. Theagarten Lingham-Soliar (2010) The evolution of the feather: Sinosauropteryx , a colourful tail1. TLS (abbreviation of the name  ) has a point, but there are more recent and probably more refined studies that were able to repeat the results (Li et al., 2010); (Li et al., 2014). Li, Q., et al. (2010) Plumage color pattern of an extinct dinosaur.Li, Q., et al. (2014) Melanosome evolution indicates a key physiological shift within feathered dinosaursc) (no quote, summary) We interpret a pigmented structure in the abdomen of Sinosauropteryx as a liver. The shape of a liver indicates a hepatic respiratory system, more similar to that of crocs than to birds. JA Ruben (1997) Lung Structure and Ventilation in Theropod Dinosaurs and Early Birds1. Air sacs (implied by pneumatic bones) are a heavy counter example to the hepatic theory. 2. You probably misidentified the structure (Currie and Chen, 2001). Philip J Currie, Pei-ji Chen (2001) Anatomy of Sinosauropteryx prima from Liaoning, northeastern China |
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Post by Infinity Blade on Sept 4, 2015 6:37:47 GMT 5
"Dinosaurs couldn't have evolved into birds because the femora of birds don't move significantly in locomotion while those of dinosaurs did."
*sigh
All this could simply mean is that birds have evolved an anatomical trait that deviates from the traditional theropod body plan, no different than how abelisaurid forelimbs are drastically different from the plesiomorphic theropod forelimb or how tyrannosaurid, ornithomimid, etc. metatarsals differ from those of the default theropod, or are these animals not theropods? And of course, one anatomical difference obviously doesn't mean an animal didn't evolve from another. Furthermore, this same logic could be applied to whatever Triassic hellasaur the BANDits believe is the "true" progenitor of birds.
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Post by creature386 on Sept 9, 2016 1:27:24 GMT 5
I know that this would technically belong into the index to creationist claims, but the CreationWiki has an article which is filled with arguments which are also frequently used by BANDits. Here's the article: creationwiki.org/There_are_gaps_between_reptiles_and_birds_(Talk.Origins)Note the obvious reliance on smoking guns, i.e. "one single proof settles everything, period". A little tip for using smoking guns, you should use pieces of proof which are a bit better described than Protoavis. It is generally agreed that Protoavis is not a valid taxon and most likely a chimera. Few paleontologists even took Protoavis seriously, but those who did (except for the original describer) generally agree that it is not relevant to discussions of avian origins: en.wikipedia.org/wiki/ProtoavisThis is such a glaring non-sequitur, you need more than one isolated piece of evidence for such a conclusion, particularly because Archaeoraptor has been exposed a year after its discovery, most dino birds endured longer. The CreationWiki then claims that there is no evidence that Sinosauropteryx (citing "evolutionist Alan Feduccia") was feathered and that Caudipteryx was a bird, both claims got addressed before. It also claims that Beipiaosaurus was a bird, citing Wikipedia as a source which completely contradicts their statement. Moreover, they conclude that because Sinosauropteryx had no feathers, Beipiaosaurus had neither.Citation needed.No, it at most follows that the most recent common ancestor of maniraptorans already had big brains, it's not as if there is a brain-size category in which all dinosaurs have to fall.Of course the source had to be a BANDit source, it was not a mistake to put the CreationWiki's nonsense in this thread. Since you guys like Wikipedia, why not actually read it? en.wikipedia.org/wiki/Dromaeosauridae#Alternative_theories_and_flightlessnessThe only dromaeosaurids where ideas of flight are taken seriously were those near the base which means Microraptor and its relatives. Also, the consensus among paleontologists is dromaeosaurids and birds being sister taxa, not dromaeosaurids being birds. I cannot access the source that claims dromaeosaurids were varieties of Archaeopteryx, but it seems to be some pop science website. The CreationWiki then makes a bunch of assertions where it claims that several bird-like dinosaurs were birds or varieties of Archaeopteryx. It also claims that paleontologists ignore any evidence of birds older than Archaeopteryx. Their general rebuttal to the transitional forms between Archaeopteryx and modern birds is rather weak.TalkOrigins was mostly showing representatives of families and they of course chose the best-known. For example Sinosauropteryx was given as a representative of its family which stretches back to the Jurassic (Compsognathus), the age of Sinosauropteryx is irrelevant to TO's point. The point was also not about the chronological order of the fossils, but about the morphological continuum ranging from birds to modern dinosaurs. |
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Post by theropod on Sept 9, 2016 2:42:51 GMT 5
"Dinosaurs couldn't have evolved into birds because the femurs of birds don't move significantly in locomotion while those of dinosaurs did." * sighAll this could simply mean is that birds have evolved an anatomical trait that deviates from the traditional theropod body plan, no different than how abelisaurid forelimbs are drastically different from the plesiomorphic theropod forelimb or how tyrannosaurid, ornithomimid, etc. metatarsals differ from those of the default theropod, or are these animals not theropods? And of course, one anatomical difference obviously doesn't mean an animal didn't evolve from another. Furthermore, this same logic could be applied to whatever Triassic hellasaur the BANDits believe is the "true" progenitor of birds. More than that, there is actually an observable trend within theropods to have a more knee-driven locomotion, i.e. moving the femur less, the closer they get to birds. Throughout that evolution, the femur becomes proportionately shorter, the ilium larger and the tail smaller. Case in point: compare Herrerasaurus to Deinonychus; long femur, short ilium and large haemal processes in the former indicate a robust tail base and slender tigh, while short femur, long ilium, small haemal processes and an absent fourth trochanter point towards a robust tigh but slender tail base, so more basal theropods had more muscle mass that retracted the femur, while more derived ones had more muscle mass that flexed the knee. So clearly more birdlike theropods moved their femora less during locomotion than more distantly related ones. This example is an extreme, but its even noticeable when you compare more intermediate taxa, like allosaurs and tyrannosaurs. So in many ways, while birds are obviously the culmination of this trend, they don’t represent an aberrant morphology at all, but the continuation of an evolutionary tendency that was present in theropods from the beginning. |
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Post by Infinity Blade on May 28, 2020 9:52:09 GMT 5
Recently Aron Ra had a livestream with Darren Naish in response to a video of someone giving a talk about why he doesn't think birds can be dinosaurs. According to Ra, this man, David Menton, is actually a medical doctor (sure enough, AiG's website says he was a professor at Washington University School of Medicine->). I therefore get the impression that Menton isn't even a qualified paleontologist, unlike the BANDits who have been cited here. But I still think this is probably the best place to share Ra and Naish's response. www.youtube.com/watch?v=8_6v2LQ8SJY^This is the whole (warning: 2 hour long) video. Because Ra was unable to show images, he has decided to fulfill a request that he break down his video outlining the key points of his talk with Naish, this time including visuals. Below is part 1 thereof. |
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Post by creature386 on May 28, 2020 11:04:20 GMT 5
Watched this video yesterday. I had no idea where to share it, but good that you found a place.
Definitely not among the more serious BANDit claims, but as long as this guy has an audience, it is worth a refutation nonetheless.
As for him being a doctor, that type of ultracrepidarianism is unfortunately very common among creation "scientists" (Werner Gitt, one of Germany's most prominent evolution deniers, is an engineer!). I've noticed that paleontologists are one of the most under-represented groups of scientists among creationists, perhaps only after evolutionary biologists. Why is this so unsurprising?
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Post by creature386 on Jun 3, 2020 19:17:08 GMT 5
Part two, for the sake of completion:
The part with the counterweight is truly fascinating.
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Post by Infinity Blade on Jun 17, 2020 4:45:11 GMT 5
And then there were three (parts).
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) has a point, but there are more recent and probably more refined studies that were able to repeat the results (Li et al., 2010); (Li et al., 2014).
