Birds

The Galatian · Jul 28, 2005

Aside from Galatians flat out lies about what I have said or implied (which is not uncommon for him),
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I assure you that I have never lied to you or about you, Helen. If you feel I've misrepesented you, I'd be pleased to see how.

I leave the rest to the other readers to see what is going on. To my mind, calling birds and dinosaurs the same sort of thing is an act of desperation.
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Since no one seems to be able to draw a line between them, it's hard to see how you could doubt that they are very closely related.

On another forum, I was asked why, if people have free choice, they choose wrong so often. The point the writer was making was that God must be stupid or incompetant or not there at all. My response included the thought that the more 'educated' and 'intelligent' the person, the more often the wrong choices seem to be made.
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My experience is that stupid people are more prone to make bad choices. Criminals, for example, tend to be dumber than the rest of us.

I presume that is because common sense gets thrown out with one's pride in one's intelligence and education a good percentage of the time.
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I think that intellectual pride is not uncommon among the incompetent as well. A recent study showed that in fact, the less competent a person is, the more likely he is to not realize it.

If there are any readers out there following any of this who don't feel they are intelligent enough to comment, don't worry about it.
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I don't think we got far enough to confuse anyone. What we've discussed so far is certainly in reach of any normal person.

Common sense is enough to see what is going on.
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It definitely helps to know the evidence, though. I know you're pretty upset with me, Helen, but a less knowledgeable person would have charged right in and started defining birds and dinosaurs. You know how little difference there is between them, and you were reluctant to do it. And I don't blame you.

You can trust that. Don't let all the word play and other garbage intimidate you into thinking you don't have what it takes to know the truth or to recognize the truth when you see it.
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Anyone can understand it. A good place to start would be to go check out some of the information on early birds/advanced dinosaurs.

http://www.origins.tv/darwin/dinobirds.htm

UTE, Galatian, I'm done with this thread. You two have totally betrayed the very brains God gave you.
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God bless you, Helen. I very much wish we could discuss things without anyone being upset. We know we disagree, but I wish we could avoid being unpleasant about it.

UTEOTW · Jul 29, 2005

"'more like' is not the 'same as.' "

You're right, of course. But the point is that there is a continuum of birds that are more and more like theropod dinosaurs and of theropod dinosaurs that are more and more like birds with a nice grey area in the middle where it is hard to tell the difference. One Archaeopteryx specimen was misidentified as the dinosaur Compsognathus for a while.

In the end, you must come to the conclusion that birds are dinosaurs if you follow the same proceedures by which you call man a placental mammal or by which you assign any other taxonomic classification. So in this case, more like does eventually lead to the same.

"I leave the rest to the other readers to see what is going on."

Yes, we have a thread on birds and some reasons why we should suspect that they are evolved from theropod dinosaurs. You have doubted this, but instead of telling what the differences are that would let us neatly divide animals as surely one or the other, you have movedthe goalposts by asking the impossible to know question of how many mutations it took to get from one to the other. It is first impossible because we do not have the genomes in question. It is also impossible because no one know where to draw the line that separates the two.

But the reader should have no problem with that.

"To my mind, calling birds and dinosaurs the same sort of thing is an act of desperation."

And I might have a different idea of what constitutes a desparate act in this thread.

"If there are any readers out there following any of this who don't feel they are intelligent enough to comment, don't worry about it. Common sense is enough to see what is going on."

If you are lurking and cannot follow the topic, I encourage you to either ask some questions or to make friends with Google and see what others have to say. Read both sides. Most people are smart enough to come to their own conclusions IF they are given enough information.

The only dumb questions are those which go unasked.

"UTE, Galatian, I'm done with this thread. You two have totally betrayed the very brains God gave you."

There is no need to get upset. I don't see any reason here to do so. It could have been interesting.

Travelsong · Jul 29, 2005

Even win the YEC's feign scientific credibility they can't help but resort to emotionalism and rhetoric.

The Galatian · Jul 29, 2005

There are exceptions. I know I get Helen upset sometimes (and I don't mean to) but she is a tough debator precisely because she comes at you with knowledge and facts.

I don't agree with her conclusions, but she does try to ground her arguments in fact.

I think there are certainly others. It's just that the rug-chewing, irrational ones are more memorable than the calm, reasonable creationists.

UTEOTW · Jul 30, 2005

Another link between dinosaurs and birds was found this year.

In China's Jiangxi province, a dinosaur was found with two eggs inside the dinosaur. Now dinosaurs and crocodiles are both part of a group of reptiles called archosaurs. If birds were to have evolved from dinosaurs, then you might expect that somewhere along the way there was a creature with a reproductive system intermediate between the two.

And this is just what has been found. The dinosaur in question, a theropod of course, has a reproductive system that shares traits with both crocodiles and modern birds.

Tamaki Sato, Yen-nien Cheng, Xiao-chun Wu, Darla K. Zelenitsky, Yu-fu Hsiao, A Pair of Shelled Eggs Inside A Female Dinosaur, Science, Vol 308, Issue 5720, 375 , 15 April 2005.

Helen · Jul 30, 2005

How do you know these are 'links'? How do you KNOW there is a continuum? Why are these not simply variations?

The truth is, they could be either without anything else to go on except the foregone conclusions/presuppositions of evolution or creation.

But if you take away those presuppositions and look only at the data, only at the fossils, you really have no idea, do you?

You say that evolution would predict them. So would creation! Creation predicts variations, and we certainly see them in the fossil record. But that does not prove creation any more than declaring them to be not variations but transitionals proves evolution.

It is when we go to the other data we find evolution impossible. And it's when you put it all together that you know evolution did not have the time or the ability to do what its proponents claim it did.

Therefore, as a creationist, I feel quite confident in classifying these finds as very interesting variations.

The Galatian · Jul 31, 2005

Here's why Helen was so reluctant to try to divide dinosaurs from birds. Common features of birds and some maniraptoran dinosaurs:

Pubis shifted to the posterior.

Relatively longer arms with clawed hands.

Large orbits in skull.

Semi-lunate carpal that permitted flexible wrist movement and grasping.

Hollow, thin-walled bones.

Opposable grasping hand with three digits, 4-toed foot, with three supporting the animal.

Reduced and stiffened tail.

Elongated metatarsals

Digitigrade (walks on toes)

Similar eggshell microstructure.

Teeth are constricted between the root and the crown.

S-shaped curved neck.

Shoulder joint arranged to allow swinging arms, useful in grasping (and also for flight stroke used by birds)

Pneumatized sinuses in skull.

Sacrum with at least five vertebrae.

Straplike scapula (shoulder blade).

Furcula (wishbone).

Ankle joint movement restricted.

Secondary bony palate.

Feathers

UTEOTW · Jul 31, 2005

"How do you know these are 'links'? How do you KNOW there is a continuum? Why are these not simply variations?"

It is not simply the fossils that lead to the conclusion of evolution. It is the total package of available information. It is a gross simplification and an attempt at distraction to try and reduce it to merely physical similarities.

Often, this other data comes in the form off genetics. And for birds, we do have genetic evidence to support the claims. As mentioned above, archosaurs are a group of reptiles that split off from the others and have some unique characterisitcs compared to the other reptiles. Archosaurs then gave rise to the crocodiles, pterosaurs and dinosaurs. Most scientists think that birds evolved from a particular group of dinosaurs although there are a few holdouts who think that the birds and the dinosaurs share a common archosaur ancestor.

In any case, one would expect birds to be most genetically similar to other archosaurs.

Axe1 Janke and Ulfir Amason, The Complete Mitochondrial Genome of Alligator mississippiensis and the Separation Between Recent Archosauria (Birds and Crocodiles)

The bootstrap support for branch b, the bird/alligator lineage, was 94%, 95%, and lOO%, respectively, in MP, NJ, and QP analyses of the aa sequences...Applying the test to nt or aa sequences, the two relationships alternative to that of joining birds and crocodilians were rejected near or above the 95% confidence level.
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And this result has been found by other researchers looking at other genetic material.

LARHAMMAR, D., and R. J. MILNER. 1989. Phylogenetic relationship of birds with crocodiles and mammals, as deduced from protein sequences. Mol. Biol. Evol. 6:693-696.

HEDGES, S. B. 1994. Molecular evidence for the origin of birds. Proc. Natl. Acad. Sci. USA 91:2621-2624.

KUMAZAWA, Y., and M. NISHIDA. 1995. Variations in mitochondrial tRNA gene organization of reptiles as phylogenetic markers. Mol. Biol. Evol. 12:759-772.

The first author also noted another way in which the different data sets come together. Mutation rates can be used with the genetic data to give an estimate of the time of divergance. The fossil record can be used to estimate this time depending on what fossils are found. Neither is exact as mutations rates may vary some and you may not have the oldest fossil available and/or the characteristics that mean that two lineages have diverged may be fuzzy. However,

According to Benton (1990), Stugonosuchus and other related fossils from the Anisian (240 MYA) are the oldest fossils representing the Crocodylotarsi, whereas Lagosuchus from the Carnian (227 MYA) is the oldest fossil representing the Ornithosuchia. This leads to the conclusion, that, based on the fossil record, a minimum divergence time for the two lineages is at least 245 MYA (Benton 1990). Even though the 242-MYA dating of the avian/crocodilian divergence is not directly rejectable by the fossil record, it is very close
to the age, 240 Myr, of diversified Crocodylotarsi fossils. The 242-MYA dating may therefore constitute an underestimate. When the evolutionary rate of the alligator was allocated to branch b (the common avian/crocodilian lineage), the divergence of crocodiles and birds was dated at 266 MYA. The application of the newly established molecular reference A/C-60, the artiodactylan/
cetacean divergence set at 60 MYA (Amason and
Gullberg 1996), produced a dating of 276 MYA for the same divergence. Taking into account that unexplorable deviations from constant evolutionary rates may affect the outcome, the difference between the 266-MYA and 276-MYA datings is not unexpected. The similarity between the two outcomes is underlined by the fact that a postulate of an artiodactyl/cetacean split at 58 MYA (rather than 60 MYA) would yield identical outcomes in the two calculations.
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UTEOTW · Jul 31, 2005

"How do you know these are 'links'? How do you KNOW there is a continuum? Why are these not simply variations?"

Not to drag this thread off topic, but this question came up a few times recently and I am going to replay my answers form those times. The two answers are not that different.

That is why I said that the most amazing part is the way all the pieces fit together.

If all you had was the line of fossils going from Tetraclaenodon to modern horses and from Tetraclaenodon to rhinos, well you might have a point. It still would be strange to have all those animals that simply lived and died to have so many different morphological traits changing together but you could assert it.

But then why would horses and rhinos genetically test as being so close together? In your view, what is it about these two that make them test as genetically closer to each other than any thing else?

You also have occasional atavisms that show up in modern horses. In modern horses, the tibia and fibia are fused. Occasionally though, a horse will be born with these two bones unfused just as they were in what the fossils tell us are its ancestors. Horses have one toe per foot and have two degenerate toes called splints on each foot. Occasionally, horses will be born with these two extra toes fully formed just a they were in what the fossil record tells us are its ancestors. Why would they have the genes for making these parts if they never had them?

I also like the example of whales. YOu have this series of fossils going all the way back to a land dwelling ancestor. A group of modern land dwelling animals with an even number of toes on each hooved foot can also trace their ancestry back to this same group of fossil animals. The creatures included are animals such as deer, antelope, pigs, camels, and hippos.

Amazingly, genetic testing shows whales as being most closely related to these very animals. Why.

The fossil whales went through stages with legs that gradually changed. The rear legs basically went away and the front legs turned into flippers. DUring development, whale embryoes still make little hind legs that are later reabsorbed. Some whales are born with fully formed rear legs. Why would they have genes for making rear legs if they did not have ancestors with rear legs? The front flippers still have the humerous, radius, ulna, carpals, metacarpals and phylanges just like your arms do. The pelvis remains up in there somewhere.

Genetic testing revelas another curious aspect of the whales. Olfactory genes fall into two general categories. Animals such fish have genes for making a sense of smell to detect odors in water. Land dwelling animals have genes for detecting odord in air. Whales have dozens of genes that match the olfactory genes of land dwelling animals. Furthermore, since these genes are useless in the water, they have accumulated enough mutations to be not functional. Why would whales have genes that are only found in land dwelling ancesotrs if they did not have land dwelling ancestors?

There are many, many more such lines of evidence. Individually, you might be able to dismiss them in turn. But taken together, they present a compelling picture whose only conclusion is common descent. There is no other explanation for the wide range observations.
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The question to be asked is what interpretation best explains the evidence that we observe. As new information comes in, it will either support your interpretation or contradict it. Support tells you that you are on the right track. Contradiction tells you that you need to rethink your theory.

The first observation that gets discussed is morphology. Now if we look at the animals that are alive today and the animals that the fossil record tells us were alive in the past, we see that the form a nested heirarchy. All by itself this could mean that all of these animals were produced by common descent or by common designer. (As a note, I am not trying to set up a false dilemma here. I recognize that there may be other explanations that could be put forward but I am purposely restricting the discussion to the two possibilities under discussion.) So you have to go to the next observation.

The next most obvious observation is genetic. If you examine all the different types of genetic material that has been tested and use it to construct phylogenic trees, you find that you get much the same pattern as you do when you arrange the fossils by morphology. Let's see how these observations stack up.

One easy test is to look at just the functional genes. These can again be used to support common descent or a common designer. Both will claim that creatures that are the most similar should have the most similar DNA.

But you can start to untangle the two by looking into further types of genetic material that is not related to the functional part of DNA. One example would be to look at retroviral inserts. These happen when a virus inserts part of its genome into its host. If this happens in a reproductive cell, then the genome of the virus can be passed on to the offspring. Since this has nothing to do with the functional part of the genome, it can shed light on the situation for us. For example, if common descent were true, then you would expect the retroviral DNA to show the same pattern as the other lines of observation. If a common designer were the true explanation, then you would expect a random distribution of the retroviral inserts when compared between the species. In fact, you see that the pattern follws that which wbe expected of common descent. The common designer option cannot explain this pattern.

If you take the retroviral discussion and repeat it with things like paralogs, pseudogenes, retrotransposons and such you will find the same result. One pattern would be predicted by common descent and another by a common designer but the patterns only fit that of common descent. For example, whales have a complete set of psuedogenes identical to what land based animals possess for their sence of smell. If whales evolved from land based ancestors, this is easily explained. But if they were recently created as is, there is no reason for them to possess such useless genes. A common designer advocate is forced into giving an arbitrary, ad-hoc explanation for this observation.

From here let's move on to other topics. Let's first loook at atavisms. We have brought a few into discussion already. Atavistic legs on whales. Two extra toes on horses. Unfused leg bones in horses. Atavistic tails on humans. The observation is that these atavisms ONLY manifest themselves in a pattern consistent with the phylogenic trees generated from the other lines of evidence. The atavisms only make parts that were possessed by their ancestors in the common descent interpretation. You never see atavisms that fail to follow this pattern. Common descent offers a simple explanation. The common designer option gives no reason why we should expect whales to have genes for making legs of humans to have genes for making tails. They are again forced into capricious explanations.

Development tells a similar story.This has the potential to get rather complicated, so I'll stick with an example already in play. We observe that whales go through a developmental stage in which they possess rear legs. Again, this shared developmental trait follows the same pattern as the other lines of evidence. Common descent offers a simple reason for this to be the case. A common designer has no logical reason to send whales through a stage with legs which must later be reabsorbed.

This can keep going for a long time. If you look at other areas of evidence, you keep coming back to the observation that all the bits always fit the tree that you get from morphology and genetics. This is true for parahomlogy. This is true for vestiges. This is true for the chronology of the fossils. Every observation that you make brings you back to these same trees.

So the question is which interpretation of the data fits the observations. The answer is that common descent offers a simple and compelling answer for each one. A common designer can be hypothesized for some of the observations but for many of the observations, the evidence is the opposite of what would be expected. The only recourse for YEers is to ignore these contradictions. BUt you really must worry about someone's ideas when they must ignore so much.
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UTEOTW · Jul 31, 2005

"You say that evolution would predict them. So would creation! Creation predicts variations, and we certainly see them in the fossil record."

Your version of creation can only say that there will be variation. It cannot say what kind of variation should be found.

For evolution, it is not surprising that we find that the hearts of birds and dinosaurs were similar. It is not surprising that we find their blood vessels to be similar. It is not surprisiong to find feathers on dinosaurs. It is not surprising to find their reproductivve systems to be similar. It is not surprising that we find their respiratory systems to be similar. It is not surprising to find all of the similar traits that The Galatian listed above.

These are the specifics that your version of creation cannot predict. That is the main point of the two long posts above copied from elsewhere. It is so arbitrary. It cannot predict any specifics and can accomodate any discovery. It is not testable or falsifiable.

UTEOTW · Aug 10, 2005

Surprise!

Another link between birds and theropod dinosaurs has been found. In this case, a tissue unique to female birds was found in a T-rex fossil.

Unambiguous indicators of gender in dinosaurs are usually lost during fossilization, along with other aspects of soft tissue anatomy. We report the presence of endosteally derived bone tissues lining the interior marrow cavities of portions of Tyrannosaurus rex (Museum of the Rockies specimen number 1125) hindlimb elements, and we hypothesize that these tissues are homologous to specialized avian tissues known as medullary bone. Because medullary bone is unique to female birds, its discovery in extinct dinosaurs solidifies the link between dinosaurs and birds, suggests similar reproductive strategies, and provides an objective means of gender differentiation in dinosaurs.
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Schweitzer, Wittmeyer & Horner (2005), Gender-Specific Reproductive Tissue in Ratites and Tyrannosaurus rex, Science Vol 308, pp 1456-1460.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15933198&dopt=Citation

UTEOTW · Aug 11, 2005

How about another bird / dinosaur link? This one has to do with how the digits on the front arms of theropods matches the development of the wings of birds.

The expression of Hoxd12 and Hoxd13 in the developing wing is consistent with the hypothesis that birds are living dinosaurs.
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See the abstract at

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15880771&dopt=Citation

Vargas & Fallon, The digits of the wing of birds are 1, 2, and 3. a review, J Exp Zoolog B Mol Dev Evol. 2005 May 15;304(3):198-205.

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