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Author Topic:   Branchial arches or biomechanical flexion folds?
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 31 of 50 (270097)
12-16-2005 3:42 PM
Reply to: Message 30 by Yaro
12-16-2005 3:31 PM


Re: A challenge
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.

This message is a reply to:
 Message 30 by Yaro, posted 12-16-2005 3:31 PM Yaro has replied

Replies to this message:
 Message 33 by Yaro, posted 12-16-2005 6:29 PM randman has replied

  
Wounded King
Member
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 32 of 50 (270106)
12-16-2005 4:11 PM
Reply to: Message 27 by randman
12-16-2005 3:02 PM


Re: biomechanical folds
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

This message is a reply to:
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Yaro
Member (Idle past 6496 days)
Posts: 1797
Joined: 07-12-2003


Message 33 of 50 (270152)
12-16-2005 6:29 PM
Reply to: Message 31 by randman
12-16-2005 3:42 PM


Re: A challenge
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.

This message is a reply to:
 Message 31 by randman, posted 12-16-2005 3:42 PM randman has replied

Replies to this message:
 Message 34 by randman, posted 12-16-2005 6:44 PM Yaro has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 34 of 50 (270154)
12-16-2005 6:44 PM
Reply to: Message 33 by Yaro
12-16-2005 6:29 PM


Re: A challenge
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.

This message is a reply to:
 Message 33 by Yaro, posted 12-16-2005 6:29 PM Yaro has replied

Replies to this message:
 Message 35 by Yaro, posted 12-16-2005 6:49 PM randman has replied

  
Yaro
Member (Idle past 6496 days)
Posts: 1797
Joined: 07-12-2003


Message 35 of 50 (270156)
12-16-2005 6:49 PM
Reply to: Message 34 by randman
12-16-2005 6:44 PM


Re: A challenge
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.

This message is a reply to:
 Message 34 by randman, posted 12-16-2005 6:44 PM randman has replied

Replies to this message:
 Message 36 by randman, posted 12-17-2005 1:54 AM Yaro has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 36 of 50 (270256)
12-17-2005 1:54 AM
Reply to: Message 35 by Yaro
12-16-2005 6:49 PM


Re: A challenge
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.

This message is a reply to:
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Replies to this message:
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bernd
Member (Idle past 3981 days)
Posts: 95
From: Munich,Germany
Joined: 07-10-2005


Message 37 of 50 (270292)
12-17-2005 10:04 AM
Reply to: Message 21 by randman
12-16-2005 2:43 PM


Re: biomechanical folds
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

This message is a reply to:
 Message 21 by randman, posted 12-16-2005 2:43 PM randman has replied

Replies to this message:
 Message 41 by randman, posted 12-19-2005 2:26 PM bernd has replied

  
Yaro
Member (Idle past 6496 days)
Posts: 1797
Joined: 07-12-2003


Message 38 of 50 (270303)
12-17-2005 10:48 AM
Reply to: Message 36 by randman
12-17-2005 1:54 AM


Re: A challenge
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:
Response:
1. Evolutionary theory is the framework tying together all of biology. It explains similarities and differences between organisms, fossils, biogeography, drug resistance, extreme features such as the peacock's tail, relative virulence of parasites, and much more besides. Without the theory of evolution, it would still be possible to know much about biology, but not to understand it.
This explanatory framework is useful in a practical sense. First, a unified theory is easier to learn, because the facts connect together rather than being so many isolated bits of trivia. Second, having a theory makes it possible to see gaps in the theory, suggesting productive areas for new research.
2. Evolutionary theory has been put to practical use in several areas (Futuyma 1995; Bull and Wichman 2001). For example:
* Bioinformatics, a multi-billion-dollar industry, consists largely of the comparison of genetic sequences. Descent with modification is one of its most basic assumptions.
* Diseases and pests evolve resistance to the drugs and pesticides we use against them. Evolutionary theory is used in the field of resistance management in both medicine and agriculture (Bull and Wichman 2001).
* Evolutionary theory is used to manage fisheries for greater yields (Conover and Munch 2002).
* Artificial selection has been used since prehistory, but it has become much more efficient with the addition of quantitative trait locus mapping.
* Knowledge of the evolution of parasite virulence in human populations can help guide public health policy (Galvani 2003).
* Sex allocation theory, based on evolution theory, was used to predict conditions under which the highly endangered kakapo bird would produce more female offspring, which retrieved it from the brink of extinction (Sutherland 2002).
Evolutionary theory is being applied to and has potential applications in may other areas, from evaluating the threats of genetically modified crops to human psychology. Additional applications are sure to come.
3. Phylogenetic analysis, which uses the evolutionary principle of common descent, has proven its usefulness:
* Tracing genes of known function and comparing how they are related to unknown genes helps one to predict unknown gene function, which is foundational for drug discovery (Branca 2002; Eisen and Wu 2002; Searls 2003).
* Phylogenetic analysis is a standard part of epidemiology, since it allows the identification of disease reservoirs and sometimes the tracking of step-by-step transmission of disease. For example, phylogenetic analysis confirmed that a Florida dentist was infecting his patients with HIV, that HIV-1 and HIV-2 were transmitted to humans from chimpanzees and mangabey monkeys in the twentieth century, and, when polio was being eradicated from the Americas, that new cases were not coming from hidden reservoirs (Bull and Wichman 2001). It was used in 2002 to help convict a man of intentionally infecting someone with HIV (Vogel 1998). The same principle can be used to trace the source of bioweapons (Cummings and Relman 2002).
* Phylogenetic analysis to track the diversity of a pathogen can be used to select an appropriate vaccine for a particular region (Gaschen et al. 2002).
* Ribotyping is a technique for identifying an organism or at least finding its closest known relative by mapping its ribosomal RNA onto the tree of life. It can be used even when the organisms cannot be cultured or recognized by other methods. Ribotyping and other genotyping methods have been used to find previously unknown infectious agents of human disease (Bull and Wichman 2001; Relman 1999).
* Phylogenetic analysis helps in determining protein folds, since proteins diverging from a common ancestor tend to conserve their folds (Benner 2001).
4. Directed evolution allows the "breeding" of molecules or molecular pathways to create or enhance products, including:
* enzymes (Arnold 2001)
* pigments (Arnold 2001)
* antibiotics
* flavors
* biopolymers
* bacterial strains to decompose hazardous materials.
Directed evolution can also be used to study the folding and function of natural enzymes (Taylor et al. 2001).
5. The evolutionary principles of natural selection, variation, and recombination are the basis for genetic algorithms, an engineering technique that has many practical applications, including aerospace engineering, architecture, astrophysics, data mining, drug discovery and design, electrical engineering, finance, geophysics, materials engineering, military strategy, pattern recognition, robotics, scheduling, and systems engineering (Marczyk 2004).
6. Tools developed for evolutionary science have been put to other uses. For example:
* Many statistical techniques, including analysis of variance and linear regression, were developed by evolutionary biologists, especially Ronald Fisher and Karl Pearson. These statistical techniques have much wider application today.
* The same techniques of phylogenetic analysis developed for biology can also trace the history of multiple copies of a manuscript (Barbrook et al. 1998; Howe et al. 2001) and the history of languages (Dunn et al. 2005).
7. Good science need not have any application beyond satisfying curiosity. Much of astronomy, geology, paleontology, natural history, and other sciences have no practical application. For many people, knowledge is a worthy end in itself.
8. Science with little or no application now may find application in the future, especially as the field matures and our knowledge of it becomes more complete. Practical applications are often built upon ideas that did not look applicable originally. Furthermore, advances in one area of science can help illuminate other areas. Evolution provides a framework for biology, a framework which can support other useful biological advances.
9. Anti-evolutionary ideas have been around for millennia and have not yet contributed anything with any practical application.
This message has been edited by Yaro, 12-17-2005 10:53 AM

This message is a reply to:
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AdminWounded
Inactive Member


Message 39 of 50 (270356)
12-17-2005 3:11 PM
Reply to: Message 38 by Yaro
12-17-2005 10:48 AM


Topic drift
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

This message is a reply to:
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bernd
Member (Idle past 3981 days)
Posts: 95
From: Munich,Germany
Joined: 07-10-2005


Message 40 of 50 (270686)
12-19-2005 6:16 AM
Reply to: Message 21 by randman
12-16-2005 2:43 PM


Re: biomechanical folds
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

This message is a reply to:
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randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 41 of 50 (270794)
12-19-2005 2:26 PM
Reply to: Message 37 by bernd
12-17-2005 10:04 AM


Re: biomechanical folds
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

This message is a reply to:
 Message 37 by bernd, posted 12-17-2005 10:04 AM bernd has replied

Replies to this message:
 Message 43 by bernd, posted 12-19-2005 4:56 PM randman has replied

  
pink sasquatch
Member (Idle past 6023 days)
Posts: 1567
Joined: 06-10-2004


Message 42 of 50 (270810)
12-19-2005 3:07 PM
Reply to: Message 38 by Yaro
12-17-2005 10:48 AM


Hey Yaro...
...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.

This message is a reply to:
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bernd
Member (Idle past 3981 days)
Posts: 95
From: Munich,Germany
Joined: 07-10-2005


Message 43 of 50 (270866)
12-19-2005 4:56 PM
Reply to: Message 41 by randman
12-19-2005 2:26 PM


Re: biomechanical folds
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:
During the fourth week 8-10 the first morphologic characteristics that typify vertebrates are formed
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:
  • The introduction into this chapter contains the following paragraph[2]:
    quote:
    The embryonic period is divided into a preembryonic period (from the 1rst to the 3rd week) 1-8, which includes fertilization, the implantation and the formation of the bi- and tri-laminar embryo, and into the true embryonic period (3rd to the 8th week) 9-23. During the embryonic period specific tissues and organs arise from each of the three germinal layers. It is the time period of organogenesis in which the embryo takes on its human form and increases its weight from 1/1'000th of a mg to 2-3 g (an increase of 2-3'000'000!).
  • The link on page [1] opens a windows with a sequence of photos picturing the developmental stages of an human embryo
  • The title in the upper left corner of [1] reads: Human Embryology
Which leads me to break down my question “Do you agree that the term biomechanical flexion folds should be avoided“, into more manageable pieces:
  • Can we agree that this site deals with human embryology?
  • Can we agree, that the link on [1] shows a sequence of developmental stages of an human embryo?
  • Can we agree, that this sequence shows that on day 28 the human embryo is almost straight
  • Can we agree, that on day 28 the first two pharyngeal arches form?
  • Can we agree that in this case flexion can’t be the cause for pharyngeal arches?
-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

This message is a reply to:
 Message 41 by randman, posted 12-19-2005 2:26 PM randman has replied

Replies to this message:
 Message 44 by randman, posted 12-19-2005 5:19 PM bernd has replied
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randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 44 of 50 (270877)
12-19-2005 5:19 PM
Reply to: Message 43 by bernd
12-19-2005 4:56 PM


Re: biomechanical folds
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

This message is a reply to:
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randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 45 of 50 (270879)
12-19-2005 5:28 PM
Reply to: Message 43 by bernd
12-19-2005 4:56 PM


Re: biomechanical folds
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.

This message is a reply to:
 Message 43 by bernd, posted 12-19-2005 4:56 PM bernd has not replied

  
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