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Author | Topic: Branchial arches or biomechanical flexion folds? | |||||||||||||||||||||||||||
randman  Suspended Member (Idle past 4927 days) Posts: 6367 Joined: |
If you have nothing to replace the ToE, what's the point of deriding it? Your question illustrates the fundamental difference between evos and myself. I don't have a need for there to be an explanation. I think it's a worthy pursuit, but an answer of we are still working on the problem is sufficient. Making up false data, overstating claims, and all the rest is not necessary and worse, it is not valid science. What I do know is a lot of evo claims have been false or overstated, and imo, some evidence strongly contradicts evolutionary theory. So imo, a good start is to go back to the drawing board, which is one reason ID theory appeals to me. It seems to want to make theories based only on empirical observation rather than trying to make the observations fit the theory, as I think evos do.
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
The questions I raised are necessary to know if the data indicates what you claim it does. No they aren't. You dont need 100 other in situs in order to accept my claim that there are specific genes with conserved patterns of expression in the pharyngeal arches consistent with a hypothesis of common descent, all you need is to look at the data in respect of those particular genes. TTFN, WK
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Yaro Member (Idle past 6524 days) Posts: 1797 Joined: |
Your question illustrates the fundamental difference between evos and myself. I don't have a need for there to be an explanation. I think it's a worthy pursuit, but an answer of we are still working on the problem is sufficient. Making up false data, overstating claims, and all the rest is not necessary and worse, it is not valid science. But you are incorrect on 2 counts. First, our current models and theories lead to usefull results. They work. Second, they aren't based on false data. They are based on the data that there is. As creos. are fond of saying, an interpretation of the data. If our 'interpretation' is currently working, it's gonna take more than attacking it to actually change it.
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randman  Suspended Member (Idle past 4927 days) Posts: 6367 Joined: |
They work in what way?
Did the Biogenetic Law work? No. Is the fossil record replete with species to species transitions? No. Are mutations random as evos assert? We have no idea. Evolutionary theory no more "works" than ID or creationism or anything. Second, they aren't based on false data. They are based on the data that there is. Recapitulation was based on false data. Claiming mutations are random is based on no real data at all. Claiming the fossil record shows evolution is false data, imo. There is no evolution seen in the fossil record. You have to "interpret" the data to include non-observables to make it work, and you have no explanation for the non-observed data not being there. Claiming peppered moths is "evolution in action" is misleading if not outright false, and on and on. Just about every evo claim is colored with overstatement and presumption.
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Yaro Member (Idle past 6524 days) Posts: 1797 Joined: |
All of these theories work in that they explain the evidence at hand and lead to usefull results. We can accuratly make predictions and test hypothesis. We can derive technology, medical advances, and greater understanding from all of these things.
If you don't think biology, medicin, embryology, or any other such area of science is usefull, then fine. Have it your way. Though I am still astounded at your continual claim of 'dishonesty'. It's funny to me that it seems to all be based on a carefully stacked pack of cards you have created. 150 year old scientific errors. A handfull of errant textbooks. And a collection of psudo-science sites. Whatever.
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randman  Suspended Member (Idle past 4927 days) Posts: 6367 Joined: |
I guess you mean medical advances like claiming the thymus, at one time, was vestigal and that we have over 100 useless organs in our body.
If anything, I think evolutionary theory has thwarted medical advances, not helped them.
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bernd Member (Idle past 4009 days) Posts: 95 From: Munich,Germany Joined: |
Hello Randman,
Let me recapitulate. I asked you two times to detail your understanding of Blechschmidts work, because I got the impression that there is a substantial difference between your and Blechschmidts understanding of pharyngeal arches. The first time you declined because you claimed that you “don’t have the whole book”, when I pressed for further details from other parts of his book, you admitted that you “don’t have the book”. Leaving aside for the moment the ethical questions, which such a behavior provokes, it shows that your understanding of Blechschmidts concept is based only on two or three sentences written by Brian Freeman. That’s a pity, because even if Blechschmidts work is outdated when compared to the current knowledge in developmental biology - his book has been published 1978 - he has something to say, at least to creationists. The first point concerns Blechschmidts methodological approach. Even before he treats evolutionary, genetic and inductive factors, he rules out that differentiation is driven by “Zweckmssigkeit” (meaning that organism are reasonable constructed ), because then ontogenesis would be the realisation of a preconceived plan. A plan implies the intention of a conscious person - which makes “Zweckmssigkeit” a reasonable concept within Theology, but not so in natural sciences. Natural sciences he claims should restrict themselves to natural or biological comprehensible processes, because ideas like “Zweckmssigkeit” don’t add anything to scientific understanding. Replace “Zweckmssigkeit” with “design”, the conscious person with the intelligent designer and you have a classical argument against ID. In order to understand the second point you have to consider that for Blechschmidt all processes during development - at least all he describes in his book - are biomechanical processes. For example the “Densation Field” I asked you to describe in you own words, explains the development of bone tissue by loss of intracellular substance due to osmotic pressure, which leads to a denser packing of cells. So lets see what this means for our “flexion folds”. Blechschmidt explains that the embryonic neural tube - due to heavy consumption of nutrients - grows faster than the preliminary aorta. The resistance of the aorta leads to a flexion of the flexible upper part, the area of the head, above the heart bulge. This in turn leads to the flexion folds. But that’s only the beginning of the story. The face of the embryo gets wider (Blechschmidt doesn’t explain why) and the folds morph into arches which cover the pharynx. Starting from this point Blechschmidt names the folds “Visceralboegen” or visceral arches (a synonym for pharyngeal arches). With the ongoing flexion the visceral arches are getting flatter which leads to the tightening and a circular orientation of the internal tissue. This leads to the development of huge vascular cavities, which form connections between the short ventral and the longer dorsal aorta. That’s how he explains the development of the “Visceralbogenaorta”.Ok, I stop here. When we now look at diagram 40 on page 43 of Blechschmidts book, which I asked you to comment on several times, we notice that the internal structure of the pharyngeal arches according to Blechschmidt does not differ from what you can find in every decent handbook of comparative morphology. Now that we have a better understanding, what morphological structure has to be explained, lets look again at the proposed mechanism.I suppose that you are not prepared to defend that blood tissues or bone structure are the result of biomechanical processes, therefore let's try to analyze the very first step: can the sequence in which the “folds” appear be explained by the flexion of the neural tube? In [1] you’ll find a quite detailed description of the embryonic phases. Please note that the first two pharyngeal arches appear already on day 28, when the embryo is almost straight. The characteristic “C” shape is typically acquired two days later, on day 30 (see [2]). Therefore we have to rule out flexion as possible cause for pharyngeal arches and consequently the term "biomechanical flexion fold" should be avoided. Can we agree on this? -Bernd References [1]Error 404: Page not found [2]Error 404: Page not found This message has been edited by bernd, 17-Dec-2005 04:29 PM
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Yaro Member (Idle past 6524 days) Posts: 1797 Joined: |
Ya know randman, this post is charactaristic of your view on science. You like to cherry pick mistakes and errors and foreget of all the other things it has given you.
If it weren't for genetics and bioinfomatics we wouldn't know which genes cause certain desieses. If it weren't for the knowledge of ToE and the concept of genetic shift, we wouldn't be able to create flu vaccines (or any vaccines at all). Page not found ToE and heredity are intrumental in isolating genetic abnormalities, detecting desieses, and reasearching adequate treatment. Infact, ToE is a major factor in modern genetics, without it genetic makes no sense! Do you think genetics is useless? But here, have fun: CA215: Practical uses of evolution. With some key points on 'usefullness' at the end:
quote: This message has been edited by Yaro, 12-17-2005 10:53 AM
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AdminWounded Inactive Member |
Yaro,
This is a thread with a very specific and focussed topic. It is always hard to maintain a clear topic in any case but with only 1 person arguing one of the positions, i.e. Randman, it is even more important that extraneous issues aren't brought in so he has to debate multiple topics simultaneously in the one thread. I think that evolution's impact on modern medicine is a very suitable topic for a thread, but not this thread. Perhaps you can compose an OP for a PNT on this topic. TTFN, AW This message has been edited by AdminWounded, 17-Dec-2005 08:11 PM
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bernd Member (Idle past 4009 days) Posts: 95 From: Munich,Germany Joined: |
Hello Randman,
should I wait for an answer to my last message Message 37 or does your silence mean you agree with my conclusion that one shouldn't use the term "biomechanical flexion fold" because - as I stated in my opening post - "Blechschmidts model to explain ontogenesis is outdated and in some respects flatly wrong"? -Bernd This message has been edited by bernd, 19-Dec-2005 12:43 PM
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randman  Suspended Member (Idle past 4927 days) Posts: 6367 Joined: |
First off, I am not sure claims of embryos across the board is correct or not. The biomechanical flexion folds deals with human embryos, but the links appear to make claims for all vertibrates.
You are claiming the folds are not the result of the tension-bearing blood vessels attached to the neural tube, and ask me to view a book I don't have. I don't have the book and cannot comment. Certainly, the Australian professor I quoted on another thread does not seem to agree with you. Not being an embryologist, I cannot say who is correct, except to say I am very skeptical of evo claims in embryology due to the horrible track record of evos making false evidentiary claims. In general, I would say that regardless of the level of tension causing the folds, I do not see the mere outward appearance of folds as homologous to gill slits. The fact is these so-called gill pouches develop into areas of the head and neck, not merely the parathyroid or whatever area evos are claiming are homologous to gills. I think making the gill pouch claim based on outward appearance reflects a biasness due to false claims and data, namely that evos for generations accepted the Biogenetic law, the phylotypic stage and Haeckel's general claims, and so there is a distortion of clear thinking here in this field. Now, if you want to advance homology based on molecular studies,that's a fair approach. I don't think trying to resurrect Haeckel's recapitulation claims works. This message has been edited by randman, 12-19-2005 02:27 PM
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pink sasquatch Member (Idle past 6051 days) Posts: 1567 Joined: |
...I would love for you to repost your reply in a topic I started a while back: Creationists benefit directly from the Theory of Evolution.
I think the points and references you bring up are very important, and wish more of the public-at-large was familar with them. Thanks.
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bernd Member (Idle past 4009 days) Posts: 95 From: Munich,Germany Joined: |
Hello Randman,
I hope you don’t mind when I treat your message paragraph by paragraph. In the first one you wrote:
First off, I am not sure claims of embryos across the board is correct or not. The biomechanical flexion folds deals with human embryos, but the links appear to make claims for all vertibrates.
I had provided two links. Lets look at the first one[1]. Your impression that the page is making claims for “all vertibrates” is probably based on this sentence:
quote: This sentence expresses that all vertebrates share certain morphologic features, for example the pharyngeal arches we are talking about. Your assumption that therefore the site doesn’t deal with a specific example, better said a specific species is wrong. To be even more specific, the whole site is dedicated to human embryology, which can be deduced from several subtle clues like:
Which leads me to break down my question “Do you agree that the term biomechanical flexion folds should be avoided“, into more manageable pieces:
-Bernd References [1] Error 404: Page not found[2] Error 404: Page not found This message has been edited by bernd, 19-Dec-2005 10:59 PM
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randman  Suspended Member (Idle past 4927 days) Posts: 6367 Joined: |
It's still not clear to me though I agree it deals with human embryos.
In the fourth week the embryo has a length of 1.5 to 3.5 mm. At the beginning of the week it is almost straight. On the dorsal side, one recognizes the contours of the first 4 to 12 somites (although the ectoblast lies above the mesoblast, the somites stand out from it). At the same time, out of the neural plate, the process of neurulation produces a hollow cylinder whose rostral and caudal ends still stand wide open. At around the 28th day 10 , at the same time as the formation of the abdominal wall and the development of the somites progresses, the first two pharyngeal arches appear. The 28th day is the end of the week, not the beginning. The link says it is nearly straight at the beginning of the week, not the end, and in any event, it seems the biomechanical analysis, on a more detailed look, involves the rate of growth for particulars in that area, not just the whole embryo. So presumably the folds can occur when the embryo is straight. In other words, on closer inspection, it appears the flexion folds refers to the fact that the way the embryo grows causes tension as some parts expand and other parts are held in tension, thus causing the folds. I did not fully recognize that intially, but at the same time, it still seems the original stance holds. However, I am not an embryologist, but the professor dismissing gill pouches does so for a reason, it seems to me, and so I am still wondering exactly why you dismiss the concept of tension here. This message has been edited by randman, 12-19-2005 05:22 PM
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randman  Suspended Member (Idle past 4927 days) Posts: 6367 Joined: |
Let me add that looking at the photos, it is pretty vague from a layman's perspective to even see where the "first 2 pharyngeal arches" are appearing.
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